These are my notes for the Rosa of the Final Fantasy IV Any% No64 speedrun. While I am very familiar with the game and the speedrun, I am nonetheless nowhere near being the world record holder in this category or any other, so there are almost certainly faster ways to do things. That said, I do periodically update this document as new techniques and strategies are discovered, so if you follow them, you're probably not doomed to be perilously slow.
This particular guide is intended for high-level PB attempts. Beginners may wish to use the marathon guide instead, as it provides extra elixirs, but otherwise, the differences are minimal. Runners using this guide may have trouble competing for the world record time, but times of 3:07 or better are definitely possible. I use this guide for my own PB attempts.
For the curious, the following is a short list of differences between this guide and what are generally considered world-record strats:
There may be additional differences, but these are the ones I can think of at this time.
While these are largely my personal notes used when I actually run the game, a number of people have been using them to learn the run, so I will briefly go over some of the more general concepts that apply to the run. However, the notes will almost certainly still assume you are generally familiar with some of the techniques used speedrunning the game (such as item duplication and run buffering). If you are unfamiliar with these, there are other resources on this site that you may wish to examine.
As I write this, there are several potential routes you may choose to run this category. These routes mostly only differ in the final third of the game, so the first two-thirds are roughly the same in any case. Here is a brief summary:
There are other routes, but they are older and obsolete. My personal recommendation is to begin with the marathon-safe version of the Rosa route. You may also choose to begin with Edge+Excalbur to get a few runs under your belt if you prefer Edge, and then to move on to Rosa once your time is approaching 3:10 or less. Once you've reached that level, you will be relying on good RNG for your better runs, and you won't want to be leaving two and a half free minutes on the table. That said, with enough luck, a 3:04:xx Edge+Excalbur time is entirely possible, if you're inclined to try grinding it out.
Unfortunately, as it turns out, levels matter a lot in this run. As such, there is a lot of research into the best ways to allocate experience throughout the run. Experience is primarily manipulated using the following facts:
The "perfect" path is a matter of personal preference and is always up for debate. I make my recommendations throughout this guide, but there are many ways to skin a cat, and you're welcome to develop your own path that suits your playing style better. However, keep in mind the following points:
In these notes, I recommend a particular experience path. However, it isn't necessary to follow it exactly, so long as the above goals are maintained. Consult some of the other guides (especially riversmccown's guide) for more information on other possibilities.
Another important aspect of any No64 run is inventory management. You end up with a very full inventory and optimizing the location of items in the inventory is essential to a good run. This guide makes some recommendations, but ultimately, you will need to come up with an inventory management scheme you're comfortable with.
You have the option of using the Mimic Glitch (AKA Carrot/TrashCan) to defeat Milon and/or Milon Z. Learning these is beyond the scope of this guide, but it may be useful to know that you only need to pick up the Carrot or move the TrashCan to the top of the inventory if you intend to utilize these strategies.
This guide makes the assumption that you are following along from start to finish. Menuing instructions assume that your characters are already equipped as per the guide, and won't list equipment that is staying the same. If you attempt to join in the middle, you may miss this or similar points.
This guide is primarily meant to serve as my notes for personal best attempts. As such, they generally tend to err on the side of less safety. In some cases, notes are made regarding potential safer strats for beginners, but they may not be entirely consistent throughout the document (especially regarding inventory management).
This guide uses the following conventions:
The following resources should prove invaluable to either help during a run or to help you learn the run in the first place:
This guide is intended to be used with a step route. The step route is not required, but it will generally save you 2 or 3 minutes if executed properly. For this guide, you should be using the no64-rosa-safe routes.
Begin the game. During the introduction, you may wish to hold down B+Right+Down immediately before the battle with the Raven, in an attempt to avoid the Raven's attack. This is known as the BRD or BIRD skip. It may or may not work for you, depending on the awesomeness of your mashing. Finish the introduction and gain control.
If you're on seed 92, be sure to take at least one extra step before you finish the introduction sequence.
Pick up the Tent (the rightmost chest) on Castle Baron 1F and then head to Cecil's room in the left tower to finish the introduction.
Walk to the chocobo forest, optionally pick up the Carrot, capture a yellow chocobo, and ride to the Misty Cave.
Walk through the cave until you reach the boss.
D.Mist turns to mist.
Continue with Fight and Jump until D.Mist falls. There is a small chance (just under 1%) of a third cycle, depending on damage rolls.
After the battle, exit the cave and head toward Mist. When you approach the last tile before the town, hold left, and then hold X. When the menu opens, release the keys, and then use the Tent. After the night is over, and Cecil lowers his arm, begin to hold right, and almost immediately after, begin to hold X (while continuing to hold right). Once the menu is open, you can release the keys.
Walk past the village tiles, and then enter Mist from the right side. Head to the weapon shop.
Head to the northwest house, enter the fireplace, and pick up the Tiara from the first chest and Change (rod) from the chest at the end of the long passage. Exit the house and trigger the cut scene.
Attempt to rearrange your inventory during the animations. Change rows at the end for fist-pump swag strats.
If you are using a step route, this is when you need to start watching which steps you get encounters on.
Continue to Kaipo in the middle of the desert. Enter the town and trigger the cut scene.
NPC movement may seem random, but it's actually reasonably deterministic during this portion of the game. Assuming you walk perfectly and don't stand around, the NPCs will always be in the same location from run to run. This will remain true until Fabul. Learn where the NPCs will be and optimize your walking accordingly.
If at any point, you are unable to execute the Run Buffer for that turn, simply switch to holding A. This is entirely random. After the soldiers are dead, simply twiddle your thumbs until the Officer retreats.
Visit Rosa in the northeast house. Mash with B to avoid talking to Rosa repeatedly. Afterward, leave the house.
Just before exiting the town (immediately after emerging from the door in the wall), take one step to the right, and then go down.
Head north to the cave and enter the Watery Pass.
Walk through the first part of the cave, recruit Tellah, and then continue to the end of the cave. In the last room, pick up Darkness (sword) and exit the cave.
Enter the other cave and proceed until you meet Octomamm.
The following turn order assumes nothing goes particularly badly. Depending on how the battle actually flows, you may need to have Tellah revive Rydia with Life1 or cure the party with Cure2. Research suggests it is optimal for Tellah to stop himself on his third turn, but you can delay this if you need to cure. If Tellah gets any additional turns after casting Stop, it's easiest to just Parry.
At this point, just continue the pattern until Octomamm dies.
Immediately after the battle, open the menu.
Exit the cave and enter Damcyan. Head to the top of the castle, watch the scene, and then take the hovercraft to the Antlion cave.
Follow the path to the second room. You may take either the left or right path, but the right path feels better to me. Your mileage may vary. Once in the second room, pick up the chest on the right side with a Life.
Take the secret passage in the second room and make your way to Antlion's Nest and engage Antlion.
Depending on damage rolls, Cecil may be able to Fight on his last turn instead of Parrying. He can do anywhere from 0-70 damage, with a median value of 54.
Walk out of the cave, board the hovercraft, and return to Kaipo, making sure to park directly to the left of the town.
Head to the house in the northeast corner of town and use the SandRuby on Rosa.
During the night, Edward will loudly play his harp and an angry monster who was just trying to sleep will attack.
You can simply hold the A button for the duration of the fight.
It's a common misconception that it's the Dancing (dagger) that makes this fight consistent. It's actually the fact that Edward is being placed in the middle slot, which offers a 25% accuracy bonus. Since the harp is a back row-compatible weapon in the American release, these factors combine to give him perfect accuracy. It also means Edward is back row-glitched, so even if you switch to the dagger, he retains his perfect accuracy. You may have seen a video of Edward and WaterHag trading misses. This is primarily a problem on the Japanese version or on the PlayStation version, where the harp is not back row-compatible, reducing Edward's accuracy substantially. In that case, you either want him in the front row or you can use the Dancing (dagger). Either way, it's irrelevant for this run.
After waking up, leave the town, making sure to take a step to the left immediately before exiting.
Take the hovercraft to the entrance of Mt.Hobs, parking directly to the left of the entrance.
Climb the mountain and meet Yang at the top.
During Yang's solo battle, you can potentially manipulate yourself out of a longer battle by checking the damage rolls against this chart and pausing for a short while if you get a bad first kick.
Once you have done 800 damage, you can stop attacking. At that point, heal or parry until Yang's turn.
Once you're down to one remaining Bomb, if Edward, Yang or Cecil died, you may wish to use your Life (if you still have it) to revive them. Otherwise, send it to the bottom.
After the battle, continue to the other side of the mountain. Continue downward and then head east to Fabul.
Head to the King's Room and offer to help. (Do not mash the B button during this dialogue.)
Now that Edward has reached level 10, he has an 82% chance of killing a Fighter with a simple Fight.
Walk to the Inn and watch the scenes.
Head down the stairs and make your way to the exit. After leaving Fabul, head for the ship to the east.
Walk east into Mysidia and go to the item shop on the right.
Head to the House of Wishes and talk to the elder. After the scene, head to the armor shop on the left side of town.
If you want additional safety during the Milon fights, you can also buy Gaea (armor). Technically, the Paladin equipment and Silver (ring) are also just for safety, but I still use them.
Exit the town and head east to Mt.Ordeals.
If you are intending to use the Mimic (Carrot) strategy to defeat Milon, ensure that Porom gets hurt on the way up the mountain. This can be done either by an enemy (e.g. during a back attack) or by your own violent hands.
Palom will need to be able to kill Porom with one casting of Fire1 in the Milon battle. Unequipped, Palom can hit her for as low as 64 damage, so she should be at 64 or lower for safety. You have slightly more margin if you do the full equipment change, however.
Climb the mountain until you reach the summit.
Once on the summit, continue until you are even with the final bridge.
If you are going to use the Mimic (Carrot) strategy, you should not equip or heal Porom. You can also opt to skip equipping the other characters, as well. You may wish to at least equip Change on Palom to make the backup strategy more effective, but the inventory management route will assume you did not do this.
Even if you're not doing the full equipment change, if you have to menu anyway to heal, you may want to put the Gaea (helm) on Tellah. It will have to be done eventually, and now's as good a time as any.
If you want an easier time if you're using the Mimic (Carrot) strategy, consider changing the battle speed to 2.
If the twins cast Comet or if your Flare rolls are horrendous, Cecil should probably give up on attacking, and you should instead just expect to use Twin a third time. You can still try, though. Sometimes it works out.
If your Porom is at full health, you should probably just abort and click that Twin tab instead.
At this point, Milon should screech "Go, my children!" Cecil's next turn should arrive before Palom uses the Cure2.
This strategy is incredibly timing-sensitive. There are many ways it can go wrong, and the only way to really get good at this strategy is to practice it over and over. Porom's first run buffer has an incredibly short window, and in my experience, you must slightly anticipate it unless you have excellent reaction times. A relatively consistent method (if you're musically inclined) is to note that the proper time to run buffer is exactly four beats of the song after you confirm Fire1 (thanks to SwimmyLionni for telling me this). Regarding Tellah casting Stop, you may have better success if you have him wait a second or two before casting. Porom's second run buffer is more important. The first might be prevented by Milon taking an invisible turn.
The notes talk about pause buffering before Porom's final turn. To execute this, immediately pause once you queue Stop. Continue unpausing and pausing quickly until you see Porom flashing. At this point, hold down L and R and unpause. This allows you to get the run buffer in as quickly as possible. This is only necessary on battle speed 1, and can also be omitted if you're confident on the run buffer timing. Do note, however, that there is an incredibly short, approximately six frame window.
Walk across the bridge and engage Milon Z.
Cecil should Fight and everyone else should use Cure2 on Milon Z.
It's unlikely you'll need to heal, but if you do, you have plenty of Life or Cure2 potions.
The experience path assumes one character (specifically Porom) dies here. If you're close to finishing the battle and everyone is still alive, you may want to kill someone to keep your experience path intact (doesn't matter who). If only two survive, that's even better, as it helps ensure that Rosa will reach level 20 before Rubicant.
Hold Up and A starting from the black screen. Release as soon as you hear Cecil's item menu trigger.
The experience path assumes one character dies here (specifically Porom). If you somehow get into a situation where two are dead, that's even better, as it helps ensure that Rosa will reach level 20 before Rubicant.
After the battle, enter the tomb and watch the scene.
After the scenes, descend the mountain and head to the chocobo forest. Catch a yellow chocobo and travel back to Mysidia.
Talk to the elder, and then head to Baron via the Serpent Road.
Go to the back of the Inn and talk to Yang.
If either Cecil or Palom are unable to kill their respective Guards, Tellah should cast Virus.
If necessary, you can do limited inventory management during Karate's first attack.
It's actually possible to trigger the end of battle earlier than that message. There are essentially four different patterns, based on a timer you start right as the battle starts fading in from the black:
Originally, I tried using musical cues, but the problem is that the music doesn't restart for the second battle.
After the scenes, head to the Baron weapon and armor shop.
Enter the Old Water-way and continue until just before the Baigan battle on Castle Baron 1F.
Move on to challenge Baigan.
Your priority is to ensure Palom and Porom are dead. If necessary, Cecil can use his last turn to hit Yang again, but you will lose your chance to menu, so you'll need to finish anything in the Kainazzo battle. Don't leave Yang alive if you can avoid it.
If you are unable to kill Yang at Baigan, your experience path becomes a little more dicey. Keep Yang alive for Kainazzo, and continue on to Dark Elf, where you'll have to make a decision during the battle.
(This assumes both twins were dead. Routing experience in the event one or both of them survives is beyond the scope of this guide.)
Head to the throne room to fight Kainazzo.
Do not mash X during the scenes, unless you're looking to mercy kill your run. In particular, once you're on the airship, pressing X at the wrong time will cause the game to lock up. Stick to A or B (or some other button) instead.
After the scenes, fly to Toroia and enter the castle. Visit Edward on the left side of the castle, use an Ether1 on Tellah and then cast Exit.
Head north to the Chocobo Village, catch a black chocobo, and fly to Cave Magnes.
Head through the cave until you reach the crystal room.
Talk to the Dark Elf. After the scene, talk to him again.
If you were unable to kill Yang during the Baigan fight, please read the below information (you can ignore it otherwise):
During the upcoming Dark Elf fight, Dark Elf will cast Weak. You have different options to fix your experience path depending on who is targeted.
At this point, you'll need to make a decision based on Cecil's first damage roll. The default pattern is below, and we'll discuss the variations afterward:
If Cecil's first damage roll is 684 or less, Yang should Fight on his second turn instead of Parrying.
If Cecil's first damage roll is 942 or greater, Cid should Fight, Yang should fight on his second turn, and Cecil should Parry on his second turn. (The run buffer after Virus is not necessary in this scenario.)
If three characters survived at Milon Z. and the opportunity for killing Tellah presents itself, take it.
After the battle, get the crystal and leave the room.
You may wish to heal Cecil, Tellah and Yang here to try to avoid menuing again before FlameDog. If you get back attacked on the way, however, you might have to menu again anyway.
Take the black chocobo back to the Chocobo Village, get a chocobo and return to Toroia.
Talk to the clerics and then cast Exit.
Board your airship and you'll fly to the Tower of Zot.
After Golbez is done taunting you, go up a floor and head to the chest with Fire.
If Yang dies to FlameDog, you'll either have to a) resign yourself to a level 16 Yang at Dr.Lugae, b) use the Life glitch to kill three extra blue dolls at Calbrena or c) revive Yang at Golbez. The level 16 Yang method is probably the simplest.
Continue to the top of the tower, remembering to ensure Cecil and Tellah are fully healed before the battle.
Killing Yang is essential to ensuring a level 19 Kain with this experience path, but keeping Tellah alive is more important (for hopefully obvious reasons). Once Yang is dead, you can simply wait on Cecil's turn for the menuing opportunity. However, you must ensure Tellah is cured if the first Delta Attack hits him.
Enter the door, watch the scene, talk to Kain and then finally watch the next scene.
Kain should be level 19 at this time. If he (for whatever reason) is only level 18, after the first two jumps, have him alternate between Fight and Jump.
The timing on this fight is very sensitive. Don't hold A to fight unless directed to do so.
At this point, Valvalis transforms into her tornado form.
If the damage rolls were decent, Kain can Fight on his last turn instead of Jumping. If Valvalis still doesn't die, just continue the normal pattern. She won't have much HP left at this point.
If Cid dies, leave him dead, as it will help Rosa's experience path. Everyone else (except perhaps Cecil) optimally needs to survive. Being fully stoned counts as death, but it can be hard to see if this is the case or not.
If you want to ensure a level 19 Rydia for Dr.Lugae, make sure Cid dies here. Depending on your exact experience path, this may not be necessary, but it is if you are following this guide exactly.
After the scenes, leave the castle and take the airship to Agart.
Use Magma on the well. Afterward, fly to the Underworld.
Enter the castle and talk to the king.
If you have more than one blue and one orange doll remaining at this point, you need to do whatever it takes to eliminate the others. Only do the following once there are two dolls remaining.
If you accidentally trigger the big doll, immediately change rows, have Kain Jump, and have Cecil keep himself healed with Cure2 potions. If you're lucky, you won't trigger the damage range that results in the dolls splitting again. (It's based on damage, not on time.)
If you are following my inventory management route, the following instructions will get everything set up for what's next. During each line of Golbez's speech, move one of the following items to the bottom: Headband, Karate, Wind, and Silver.
There are three different Silver items, for a total of six items.
During the first Demolish animation, equip Fire (sword) and move the single Dancing to 7L (next to Prisoner).
During the second, swap the stack of Dancing and Legend. Then swap Ether1 and Prisoner.
Finally, during the Mist attack, swap Gaea (helm) and Tiara and then swap Change (rod) and the stack of Dancing.
Your path through the Dwarf castle (especially regarding when to walk and when to cast Warp) may vary significantly depending on your step route. Your step route instructions supersede anything written here, but don't forget to cast Warp to get the crystal. In particular, it may ask you to cast Warp up to three times (in addition to the first warp). The priority order for these warps is 1) the Dwarf (axe) room on the way down, 2) the throne room and 3) the stairway in the right tower.
After the scenes, open the menu and cast Warp.
Get the crystal, and then walk down out of the crystal room. Leave the throne room, and go east to the shop area.
Head into the east tower and pick up Dwarf (axe) on the first floor and Strength (ring) and Elixir on the top floor.
Return to the shop area and go to the armor shop.
If you are on pace to have a level 16 Yang at Dr.Lugae, give the Strength (ring) to Yang instead of Kain.
Travel through the passage underneath the Castle to the Dwarf Base. Heal at the pot, exit to the Underworld, and then make your way to the Tower of Bab-il.
Enter the Tower of Bab-il and make your way to the CatClaw on 3F. Collect the chest and continue walking until just before Dr.Lugae.
Approach Dr.Lugae to begin the scene.
After Cecil targets Dr.Lugae the second time, you can basically hold A until the fight is over. Yang may not be sufficient, in which case Rosa or Rydia will most likely finish the job.
In case you were wondering, the Mute cast is for timing purposes only.
If Cecil gained a level during the Dr.Lugae battles (he does if you're following the experience route), it becomes absolutely imperative to equip the second CatClaw on Yang. Otherwise, you're going to have a bad time with random battles.
If equipped on Yang, remove the Strength (ring) at this time and put it on Kain.
After the battle, head to the Super Cannon. Enter the room and prepare to battle.
Watch the scenes, wipe your tears away, and make your way out of the Tower of Bab-il.
After the scene, fly to Baron and land next to the castle. Wait a fraction of a second, and then enter the castle. (If you don't wait, you will instead walk onto the castle tile without entering.)
Head to the right side of the castle and get Cid's lackeys to install the hook on your airship.
Fly north to Mt.Hobs, pick up the hovercraft, fly northwest to Eblan, and finally take the hovercraft west to the cave.
Make your way through the first room of the cave until you enter the "town". Enter the weapon and armor shop (second door from the right).
Continue through the cave until you meet up with Edge, making sure to pick up the two Elixir chests on the way. (When you return to the first room after the town, they are the two chests in the secret passage.)
Equipping Cecil here is primarily done to remove the Dwarf (axe), which would cause problems in the next boss battle if left equipped. Your step route may instead direct you to keep it on until just before Edge's parents instead. Either way, it must come off before that battle, unless you want to lose 10 seconds.
Head through the Tower of Bab-il until you reach Edge's parents. If you didn't remove Dwarf, do so now.
After this, your only task is to wait the battle out. You can use the animation and text box time for inventory management, but you will lose time by doing so. If necessary, you can also have Edge Dart any extra blades you have lying around, but that obviously wastes even more time.
At this point, Rubicant will cast Glare, most likely leaving one of your characters dead:
There are a few seeds that will want you to put the Dwarf (axe) back on immediately. Otherwise, you can wait until the next menu. That said, if you have the opportunity, it won't hurt to throw it on during the Rubicant battle. It's just that in almost all cases, it's not worth the the extra menu out-of-battle.
After the scenes, enter the crystal room and then proceed through the last few rooms of the tower.
Fly to the Castle of Dwarves and land to the left of the castle.
Enter the castle and visit Cid in the infirmary.
If you already put the Dwarf (axe) on Cecil, you obviously don't need to do it again.
Fly to the sealed cave, enter, and watch the scene.
Fly back to the Castle of Dwarves and go to the throne room. After the scene, cast Exit and fly to the Overworld.
Fly to Mysidia, land directly to the left of the town and watch the scene.
You step route may ask you to either walk or fly to the Big Whale. It seems silly to fly two tiles, but it can potentially save time.
Board the Big Whale and fly to the moon.
Fly to the Lunar Path and follow the path to the Lunar's Lair. After entering and recruiting FuSoYa, make the trek back to your airship and fly to Earth.
After watching the scenes, make your way through the Giant of Bab-il until you reach the Passage. You generally want to wait until immediately before the grind fight before you do this menu. If you're on a step route, this is easy. If not, you may want to menu immediately just in case you run into the grind fight on the way. However, back attacks from certain enemies will be more annoying in that case.
This fight is somewhat complicated, so instead of a detailed command sequence, we'll instead look at the three phases of the fight. The first phase depends on exactly what type of battle you get:
If Edge is in the front row (in other words, in any case except a back attack), you might wish to have eithe Rydia, Rosa or Cecil use Change on their first turn. This will minimize the chance of killing the searcher early.
If you have a chance during a Beam attack, you should do some minor inventory management. If following my inventory management route, I recommend swapping Strength and Dwarf and then swapping IceBrand and Karate.
The following will need to repeat for five cycles (note that Edge does not get a turn for the first cycle):
This fight has very difficult timing, and things may go wrong. The most obvious failure is Rydia going before FuSoYa casts Weak. You can prevent this by delaying Rydia's Fight if the Searcher's text box pops up during her turn, but the exact timing of this is difficult to describe in text. Rivers McCown suggests no longer holding A on Rydia's turn after the second cycle. If Rydia does end up going before Weak, the character after FuSoYa should hold A the rest of the fight.
The battle speed 2 version of this fight appears to be 100% consistent, so using that is highly recommended.
A detailed strategy for recovery if things go wrong is beyond the scope of this guide.
Ultimately, you need to kill 18 dragons. Each Life use counts as an additional dragon kill.
After you have killed the requisite number of dragons, complete the following tasks:
There are only a few random formations that pose a potential problem for a post-grind Rosa, so Edge is revived to help with those if necessary.
Continue on to the Elements battle.
If someone unexpectedly died in a battle more than once up to this point, and Cecil survived, there is a strong risk that he will be on pace to reach level 28. You may wish to use the Experience Route Calculator to help determine for sure.
If Cecil is on pace for level 28, it's absolutely imperative to ensure he dies for the Elements battle. You can then revive him for the CPU battle if desired.
At this point, not every turn is listed, but Cecil, Edge and Rydia should focus on making sure Cecil and Edge are dead. Afterward, Rydia can equip Change and then parry.
If FuSoYa somehow gets his final turn before Rosa gets hers, have him cast Ice-3 on Milon instead, and then Rosa can follow up immediately with a direct Cure4 (which will hit first).
The most annoying thing about this fight is that the pattern changes depending on how long everyone stays alive. You want to finish the fight with Cecil and Edge dead. It doesn't matter if Rydia survives or not, but if she survives, she'll ultimately be level 27 instead of level 26, which doesn't really affect anything.
With regard to FuSoYa's final turn, there is plenty of time to do what needs to be done with the inventory. As long as you enter the Black magic menu before White is finished, you're fine. Alternately, you can just try to finish everything during Rydia's turn.
If you're unable to get Change on Rydia by this point, you can either equip it later and accept that your inventory is not going to be quite right, or just do an extra menu to put it on before you dupe Gungnir.
After the scenes, board the Big Whale.
Sometime before Zeromus, you'll want to duplicate Kain's spear in a battle, ideally before you pick up any chests.
Enter the crystal room, and begin your descent into the Lunar Core. Along the way, you want to collect the chest with White (robe) in one of the rooms on B5. It's the lone chest in a room shaped like an upside down U.
If you are using a step route, you will potentially need to pick up one of the chests with a Ninja star. This guide does not require one in its Zeromus battle strategy, but the chest is in the step routes. There are three potential choices (Subterrane B6, Core B1 and Core B3), and the step route will tell you which to pick up. If not using a step route (or if the route is an older route and doesn't tell you), pick up the one on Core B3, as it has the shortest walk. If you don't need one for your Zeromus fight, however, don't bother picking it up unless you're on step route.
Continue the descent until you reach the final battle. If you run into any formations of Red D. x1, it's probably faster to have Kain parry and for Rosa to cast Exit. The battle itself will take longer, but you'll escape the Heat Ray, which might make healing less necessary.
Approach Zemus to begin the final cutscenes.
The below strategy is very timing-sensitive. I recommend that you practice it several times. Be prepared to use a backup strategy (cast Bersk on Kain and have Rosa cast Cure4 after damage) if you notice Zeromus's actions no longer match the below list.
Practice counting the damage from Kain's attacks. The more accurately you can measure this total, the more likely you'll be able to choose the most optimal action on Kain's final turns. This guide assumes you are able to count Rosa's first White cast and at least five of Kain's attacks, but recommendations will be given if you are unable.
Zeromus casts Big Bang and shakes.
Zeromus casts Big Bang.
Zeromus shakes and casts Big Bang.
Kain's last actions can vary depending on the damage rolls in the fight. If you weren't able to count any damage, your best bet is to have Kain immediately use the Elixir, which will give you a 92.6% chance of success. Otherwise, use the below chart, which assumes you counted Rosa's first White and at least five of Kain's attacks:
|White + 5 Attacks||White + 8 Attacks||White + 12 Attacks||Kain Action|
|less than 19830||less than 26606||less than 36238||Fight|
|greater than 19830||greater than 26606||greater than 36238||Use Elixir|
If you run buffer Rydia's second Virus cast (even if Kain used an Elixir), there is a chance Rydia will get an opportunity to reflect a third virus. It may be worth taking if you're concerned about your damage rolls. Eventually, more specific guidance will be given here.