Speedrun Walkthrough

Estimated Run Time: 85-100 minutes

The speedrun for this game is not very RNG dependent. While there are random factors that can save or lose you a few seconds here and there, the run never relies on a random event to continue. Most of the little RNG elements are in the first 4 episodes. After that, it becomes a very execution heavy run.

General Notes: 
- Use Killia as main killer. Chosen because of Overload, access to 2 elemental skills, and attack boost/multiple turns during Revenge Mode making him OP later.

- 4 Warriors are created for throwing purposes.

- Episodes 1 through 4 are fairly standard (and is very reset heavy), consists of using items to heal and evilities to prevent status.

- Cheat shop is used to gain easy levels during the required Item World trip in Episode 3.

- Short grind session after Episode 4 (about 7-9 minutes)
- Killia is placed in Foot Soldier Squad with 10 characters.
- Evility 'Shaking Excitement' is used to power up stats and one-shot most non-boss enemies.
- Most enemies are one-shotted until Episode 12
- Main way of clearing the later maps fast is activating Revenge Mode and using Squad Attack to defeat critical enemy squads, combined with Killia's Overload.
- A Spear is used as the main weapon from Episode 5 onwards

Why Spear?
- Runs off one stat (ATK)
- Ranged weapon
- Has plenty of AoE skills
- Many of the more annoying enemies (Sage, Horsemen, WRESTLERS!) are either weak to Spear or do not heavily resist it. Those that do resist it are usually one-shotted anyways

The "Sacrifice Technique"
This is one of the most important strategies used in the run.
Offer up 3 weak units to the enemies and have Killia out. The weak units will all hopefully die next turn, and Killia will more often than not, go into Revenge Mode. Think of your weaker units as "fuel" for Revenge Mode.

Enemy Skill/Weakness Recommendations

Archer - Spear/Ice (Neutral)
Dark Knight - Ice
Sage - Spear
Pirate - Fire, Spear
Succubus - Fist
Armor Knight - Elemental Skills, Axe, Resists Spear at 20%, Sword at 30%
Zombie - Sword/Spear, Fire
Twin Dragon - Ice, Resists Sword/Spear
Orc - Ice
Shroom - Fire, Sword
Valkyrie - Wind, Fist
Warrior - Ice, Fist
Horseman - Wind
Sabercat - Spear/Ice
Imp - Fist (-40%), Sword
Mothman - Resists Fire/Ice (25%), Sword 0%
Professor - Fire
Nine-Tails - Ice, Spear
Wrestler - Spear/Ice

Bloodis - Fist
Void Dark - Fist

***********Episode 1***********
Note: Normal attacks are primarily used here

Killia normal attacks front enemy, end turn.
All living enemies should attack him, ideally Killia will double counter and kill two of them.
Normal attack last enemy, hope it one-shots or you get a counter.

After fight, skip bonus gauge/MVP tutorials

Go to Recruiter NPC, skip through dialogue
Make 4 Good-for-Nothing Warriors.

Move Killia towards nearest enemy one space, end turn. Move towards nearest enemy and attack.
Keep moving towards enemies and attacking them to death. When near Logan, end your turn at a 'wall' so he doesn't Triple Strike you.

Move towards enemies and attack. Everything should be one-shotted barring a bad damage roll.

Move towards enemies and attack. Hopefully Killia will counter a lot otherwise you're losing time.

Move towards enemies and attack. If needed, use Mint Gum to heal (<60 HP at stage start).

***********Episode 2***********

Go to Equip shop, buy Slippers, Kitchen Knife (latest sword) and Cotton Bandana.
Go to Skill shop. Get Mean Guy evility for Killia.
Equip evility and new equipment on Killia. Set Kitchen Knife as main weapon.
Go to Item shop. Sell all items. Buy 11 Hard Candy, 2-3 Cafe Au Lait, 4 Fairy Dust.

Kitchen Knife is used because Zombies are slightly weak vs sword.

Talk to Prinny above the shops you just visited. Head to Dimension Prinny afterwards.

Attack Geo Symbol on blue tiles with Killia. Kill the enemies with normal attacks

Use an item on the first turn. Move counterclockwise and kill most enemies with normal attacks. Kill any Slimes with Exploding Tiger, which Killia should have learned before you encounter the Slimes. Use regular attacks on other enemies.
If a Skull and Zombie line up nicely towards the end, Blade Rush them.

Move Exploding Tiger to top of skill list. Use a Hard Candy/Cafe Au Lait first turn. Move towards enemies and kill Slimes with skills, Zombies via Blade Rush if lined up nicely. Normal attacks on Thieves. 
Move to the spot that is 1 down, 3 right from the purple Geo Symbol to manipulate both of the Imps to line up in Exploding Tiger range.

Attack Witch on left with Killia (normal attack). Use two Warriors to lift Null Geo Symbol and throw it to the blue Geo Symbols. Move forward to destroy Geo Symbol near Zombie.
Move down and attack nearest enemy. When Mage drops down and 3 units are lined up, use Blade Rush. Use normal attacks to kill everything else.

Attack nearest 2 Zombies to the left with normal attacks. Use Blade Rush if you can hit multiple Zombies. If poisoned, heal with items. Use Exploding Tiger from behind on the boss.

***********Episode 3***********

Talk to Squad NPC, put Killia in a squad, Capture Squad preferred as it is first on squad list.
Go to Pleinair, set Killia's subclass to Warrior, attempt to pass 'Better Items' bill with Killia and hope it succeeds (about 60% chance)
If Bill does not pass, pass it with someone other than Killia.
Once Better Items bill is passed, attempt to pass Cheat Shop bill with someone other than Killia (Christo, Geese, and Red Magnus have enough Mana). This is about a 50% chance to succeed.
Buy Jewel Blossom (sword), Life Jacket x2. Go to Skill shop, buy Poison Vaccine, Tough Guy. equip all on Killia (keep Slippers).
Go to Item Shop. Sell all items and buy 9-10 Cotton Candy, 2 Yam Starch, and 4-5 Fairy Dust

Deploy 2-3 sacrifices. Have Killia attack the two Slumber Cats to the right with Exploding Tiger. When in Revenge Mode, target Slumber Cats that are above you or any Alraune with Squad Attack. Use normal attacks on everything else.

Kill passive Warrior and Valkyrie with normal attacks. Stay to the right and use normal attacks on the Slumber Cats. Move towards the left and take out the other Slumber Cats with normal attacks. Once Killia gets into Revenge Mode, Squad Attack the Imps.

Kill the initial Archer/Slumber Cats with normal attack/Exploding Tiger. Squad Attack the Imps. The group of Archer/Warriors should be taken out with Exploding Tiger.

Move Killia down to the poison pool, and stay there. Enemies should follow you and get poisoned. Focus on enemies that can be killed with one hit with Exploding Tiger. 
If Killia gets into Revenge Mode, use Squad Attack on a Valkyrie that has a Healer in her squad.

Talk to Dimension Prinny for scene.
Put Killia in Foot Soldier Squad, make him leader, then fill the remaining empty spots with units
Go to Cheat Shop, move EXP % to 160% and turn up enemy strength to max.
Go to Item World NPC, enter Gate Key.

Item World
When in the 1st level, move Squad Attack to be 2nd from top on Killia's skill list.
Basically kill every enemy on the map until Gate Key is level 10. Squad Attack kills every enemy except Gatekeepers
Ideal RNG involves getting Mystery Rooms that give levels (Fortune Teller Good/Great Luck, Arena) and/or level spheres/fish, as well as floors with favorable enemy layouts (low enemy count, no enemies on islands, etc)
Bad RNG involves unfavorable Mystery Rooms, Proto Darkdeath appearing, invincibility/reverse damage panels, and enemies spawning on islands.
If you have to go all the way to floor 10, get Killia into Revenge Mode by sacrificing units and Squad Attack everything. Defeat Item General through normal means.

Once item reaches level 10, immediately exit via Gency Exit.
Turn enemy strength down to lowest setting at Cheat Shop. Heal up and enter next story map.

Deploy sacrifices to the left. Have Killia Exploding Tiger the boar enemy to the right. Once Killia is in Revenge Mode. Squad attack the enemies to the left. Kill off other enemies. Ignore the Mothmen at the top and any enemies near them, as the Mothmen should finish them off on their own.

***********Episode 4***********

Buy 100 Thimbles (first Fist item)
Go to Skill shop. Get Paralysis Vaccine, Weaken Vaccine, Muscle Increase evilities.
Equip Paralysis Vaccine and Muscle Increase on Killia

Find Yellow Prinny in base (top left of base, in a corner)

Exploding Tiger on Prinnies. Squad Attack boss Prinny's squad if you get in Revenge Mode.

Move forward, Exploding Tiger on things. Squad Attack final group. Orcs in cross formation can be manipulated to line up.

Make tower of 5 (4 Warriors + Killia, Lift Killia from Base Panel), throw Killia to up-right area of the map. Attack the Null Geo Symbol.
Warriors will get killed triggering Revenge Mode. Squad Attack the enemies below Killia, defeat the enemies to the left with Exploding Tiger.

4-4 (Needs refining)
Deploy sacrifices to trigger Revenge Mode. Switch to spear (?), then Squad Attack Archers. Defeat other enemies with Exploding Tiger.

Move forward, kill enemies with Exploding Tiger. Use Cotton Candies to heal yourself/Usalia if needed. Squad Attack on whatever hits the most units. Very luck-based.

***********Episode 5***********

We'll take about 7-9 minutes to grind first before continuing.
Add a character to Curry Connoisseur squad.
Go to Curry NPC. Make curry by using Hard Candy as base, use all Thimbles as other ingredient.
Go to Cheat Shop. Set Enemy strength to 16 stars. Max out on EXP % (200%)
Buy 20 Taiyaki, Machete (Sword), 100 Thimble. Equip Killia with Machete.

Setup your Evilities as follows:
Mean Guy
Tough Guy
Weaken Vaccine
Poison Vaccine
Paralysis Vaccine


Do 2-1 three times. After the 2nd clear, eat the Curry and make another one with Taiyaki as base ingredient, 100 Thimble as other ingredient
During one of these fights, Magichange Usalia with Killia at least once.

To do 2-1 
Have Killia pick up green Geo Symbol, throw it at a Zombie. Have a Warrior pick up Geo Symbol on yellow tiles, throw it to green tiles. Kill everything with skills.
Hellfire Shot should unlock during first battle. Move it to the top of the list, and Exploding Tiger should be 3rd on the list, below Squad Attack.
Once you get Hellfire Shot, use it to hit everything in this grind session.

Do 4-2 twice. Killia's level should be around 130 when finished.

To do 4-2 - Braveheart Killia. Keep using Hellfire Shot and heal with items as needed.

Buy 3 Falcon Shoes, equip all of them on Killia. Buy a Fist weapon (Brawler's Cestus), latest Axe (Windblade War Axe), and the latest Spear weapon (Floral Spear), make spear Killia's main weapon and fist as sub weapon.
If Killia has mastered the Warlord class (which he should have), go to Skill shop. Buy Shaking Excitement evility. 

Make Killia's evility lineup (7 slots to work with)

Shaking Excitement
Poison Vaccine
Paralysis Vaccine
Waeken Vaccine

**************Back to Episode 5**************

Poke (aka normal attack) the Valkyries with your spear. Hellfire Shot Skulls, then Hellfire Shot the Gunners. If in Revenge Mode, target either the Skulls or Gunners.

Go up and kill the red Zombies/Slimes with Hellfire Shot.
Once no more Zombies spawn, or all red enemies are gone, get into Revenge Mode and Squad Attack a green Zombie below to kill off almost every enemy.

Move up, Hellfire Shot Maids, then red Zombies. Move up again, Hellfire Shot the middle 3 enemies, then clean up. If Hellfire Shot can't hit multiple enemies, poke them.
Possible manipulation at top area?

Head all the way down left. Poke the Chimera you encounter. Most of the stage is using Hellfire Shot to hit the most enemies, and at least one Squad Attack thrown in somewhere.
If the Healer and other Chimera position themselves such that they can both be hit with Hellfire Shot, go for them first.

Hellfire Shot everything. Target areas where Hellfire Shot can hit the most enemies. If in Revenge Mode, Squad Attack the Maids.

***********Episode 6***********

Start next stage immediately.

Head forward and poke Lady Samurais. Use Hellfire Shot to kill Ninjas. Exploding Tiger on Izuna. Stay one space away from Ninjas so their Evility doesn't kick in.

Move Killia to area with 3 Lady Samurais and kill them (Hopefully he doesn't go into Revenge Mode during this time). Destroy Geo Symbol, kill all enemies in big red area. If Revenge Gauge close to full, get into Revenge Mode, Squad Attack enemies in the big red area.
Normal attack anything in spear range. Move to end and defeat lone Ninja via Hellfire Shot.

Deploy 3 sacrifices. Move them to the right. Killia moves to the left. Focus on killing Ninjas. Get into Revenge Mode. Squad Attack a Slumber Cat. Kill any Ninjas remaining with Hellfire Shot.

6-4 (Needs more investigation)
Defeat group of 5 Orcs to right. Go for the boss (Horseman). Move forward to the main battlefield and Hellfire Shot any enemies in the way. If in Revenge Mode, Squad Attack whatever is remaining. The boss is best taken care of with normal attacks.

Switch weapon to Fist. Use normal attacks until you win.

***********Episode 7***********

Start stage immediately

Move clockwise. Use Hellfire Shot on everything and hope it all connects. Squad Attack Gunners if Revenge Mode is triggered

Move forward. Hellfire Shot everything. Squad Attack Shrooms if Revenge Mode is triggered

Hellfire Shot everything. Get into Revenge Mode and Squad Attack a Gunner (This kills the Thief that's out of reach)

Poke bears on bottom area with your spear. Move closer to the bottom of the cliff, then climb up and Hellfire Shot the Armor Knights. Hellfire Shot everything else.

Use Hellfire Shot to take out 2 Red Skulls first, then focus on other enemies and kill them with Hellfire Shot.
Equip Fist when only Bloodis is left. Get into a counter war with him.

***********Episode 8***********
Dark Testament

Start stage immediately

Dispose of the Magic Knights through normal attacks with spear equipped. Defeat left one, then the right one.
Head towards the Orcs and use Exploding Tiger to kill them.
Once the Orcs are gone, the Eryngi will be in a T formation. Hellfire Shot them.

Head up. Hellfire Shot the two Armor Knights. Get rid of the Imp on green panels.
Head towards the blue area with 3 Imps and end your turn near them. Get into Revenge Mode and Squad Attack the Imp on the blue panels. This kills off a Gunner and Mage that's far away, plus an Armor Knight.
Clean up the rest of the enemies with Hellfire Shot.

Make tower of 4 Warriors. Throw them to the yellow Succubus at the upper end of the map. Throw the Succubus out of bounds.
Have one Warrior throw Killia forward from the base panel. Killia moves to other yellow Succubus and throws her out of bounds.
Next turn, have Killia kill the Professor, and move the Warriors towards the center and end turnso they can be sacrificed to trigger Revenge Mode. 
Squad Attack any Succubus once in Revenge Mode (Do not do so while next to one due to their Evility). One Magic Knight will come towards Killia. Take her out. 
Head over to last Magic Knight and poke her.

Warp to the panels, take out the enemies with Hellfire Shot. Use Exploding Tiger on the Succubi.
Orcs will usually live a Hellfire Shot, so end turn and they will die next turn.

Switch weapon to Fist. Use normal attacks until you win.

***********Episode 9***********
Scorched Flame

Buy latest spear, two Shell Shields and Angel Shoes. Equip them to Killia.

Throw Killia to the group of 4 enemies. Hellfire Shot them and move Killia left towards the other enemies. When in Revenge Mode, Squad Attack female Brawlers to kill off one Wrestler at the end.
Head over to kill the other Wrestler once other enemies are dead.

Most enemies should be one-shotted due to the Geo effects. Attack, Hellfire Shot, etc. Use whatever hits the most enemies.

Attack the Slumber Cats and Nekomatas with Hellfire Shot. Use Squad Attack on the Lady Samurais once Revenge Mode is attained.

Hellfire Shot the Imps and Lady Samurais. Head towards the right. If you get into Revenge Mode. Squad Attack the Warriors. Exploding Tiger the Wrestlers at the top

Get into Revenge Mode by sacrificing 3 units, Braveheart Killia with Usalia and have Killia Squad Attack the middle enemies. 
Take care of the other enemies with Hellfire Shot. Focus on Chimeras first to get rid of stat debuffs

***********Episode 10***********
Toto Bunny
Start stage immediately

Get into Revenge Mode by sacrificing units, Squad Attack on a Zombie. Clean up everything else with Hellfire Shot.

Go left. Hellfire Shot Mothmen. Hellfire Shot 2nd group of Mothmen. Get into Revenge Mode. Squad Attack whatever hits the most enemies. Clean up rest with Hellfire Shot.
Manipulation (?)

Head up, end turn. Thief will throw a Zombie towards you. Defeat her and the Zombies near her with Hellfire Shot.
Head towards rest of enemies and Hellfire Shot them. Use Squad Attack on whatever hits the most enemies.

Hellfire Shot the nearest group of 3 Rabbits. Hellfire Shot another group of 3 to the right. Wait two turns. Hellfire Shot closest group of Rabbits.
Get into Revenge Mode. Squad Attack the largest group of Rabbits. Clean up the remaining group.

Braveheart Killia. Make a tower of 4. Throw Killia towards Majorita. Defeat Majorita through normal attacks. Hellfire Shot enemies and Squad Attack something if in Revenge Mode.

***********Episode 11***********
Toto Bunny Castle

Eat Curry. Head to Cheat Shop and get EXP% to as high as it can go.

Hellfire Shot Maids on the sides. Squad Attack Orange Maids. Clean up rest with Hellfire Shot.

Have Killia move forward. Deploy 3 sacrifices. They will die and activate Revenge Mode. Squad Attack Rabbits. Clean up Maids through whatever means.

Get a unit out, throw Killia forward. Move him so that he is one space away from a Maid and end turn. Pick up and throw nearest Maid towards exploding barrels.
Head towards the other Maids and end your turn one space away from the rightmost Maid. Defeat the remaining Maid with Hellfire Shot.

Throw Killia towards Maids. Take out the 2 Maids in front and move him forward. Use Hellfire Shot on wherever it hits the most enemies. Squad Attack should be used on a Maid group.

Make tower of 4. Throw Killia towards Majorita. Poke her to death. Squad Attack and Hellfire Shot remaining units.

***********Episode 12***********
Fortress de Gaulle
Buy latest spear and armor x2 (Duralumin Shield). Equip all to Killia. Keep Angel Shoes.

Deploy Killia and another non-Prinny unit as a decoy. Kill Twin Dragons and Orcs with Exploding Tiger, then head up and take care of Imps with Exploding Tiger.

Throw Killia to the other side. Use Exploding Tiger on everything.

Braveheart Killia. Head towards Nekos/Succubi, Hellfire Shot them. Head over and get into Revenge Mode. Squad Attack something. Clean up whatever is left.

12-4 (Needs more investigation)
Braveheart Killia. Hellfire Shot Armor Knights. Move forward, attack minions with Hellfire Shot (Magic Knights) or Exploding Tiger (everything else but boss) until dead. Squad Attack the Imps.
For the boss, equip Windblade War Axe as sub-weapon and use Spear skills on it.

Exploding Tiger on Twin Dragon in front, get behind Orcs in cross formation and Hellfire Shot them. Abuse infinite move and line yourself up to Exploding Tiger the rest of the enemies from the side. 
Takes about 20 seconds.

***********Episode 13***********

Start stage immediately

Hellfire Shot things. Focus on Shrooms, then Alraunes. Squad Attack Nekomatas (To kill Fairies). 

Attack the 3 nearest enemies. Head down and right. Enemies should come closer. Hellfire Shot things. Squad Attack Fairie if in Revenge Mode.

Sacrifice some units, Squad Attack nearest Slumber Cat. Hellfire Shot should kill everything else. 

Kill Slimes and Fairy via Hellfire Shot. Get into Revenge Mode in center area, Squad Attack a Mothman. Clean up rest.

Killia can move 3 times per turn. Braveheart Killia. Head towards Bloodis. Avidya Holy Water on Bloodis until he falls. Hellfire Shot everything else.

***********Episode 14***********

Equip 3 Shoes.

Get into Revenge Mode ASAP (sacrifice 3 characters if needed). Squad Attack should one-shot whole map.

Kill nearest group of 2 Valkyries with Hellfire Shot and deploy 1 sacrifice. Defeat the other Valkyries, then summon a Netherworld to remove lasers. 
Take one of the yellow warp panels and head towards the nearest Thief. You should get into Revenge Mode next turn, so use Squad Attack on a Ninja/Magic Knight/Professor 
Activate Overload and take out the Thieves remaining through whatever means.

Kill first 3 groups of Prinnies with Hellfire Shot. When at the bottom area, go into Revenge Mode, Squad Attack any Prinny to kill everything.

Go up as far as you can, kill the group of 3 Wrestlers with Hellfire Shot. End turn. Next turn, move forward two spaces and end turn. 
Wrestlers will end up in a nice formation.
Move back to Base Panel and kill the other Wrestlers with Hellfire Shot. Deploy 3 sacrifices and end turn. Squad Attack any male unit. 
Activate Killia's Overload and kill Valkyries and Archer yourself.

Revenge Mode, Squad Attack, Overload, destroy remaining units with spear skills, which are now wind elemental

***********Episode 15***********
Outer Dark Demise

Buy 2 Spartan Shield and Dynastic Guandao. Buy 20 Eclairs

Defeat Armor Knights to the right with Hellfire Shot and send out 3 sacrifices. When in Revenge Mode, activate Killia's Overload, use his first move to get rid of any Armor Knights near the Base Panel. Use Killia's second move to Squad Attack any Lady Samurai to wipe out the Ninetails as well. 
Make a tower of 6 and throw Killia towards the area with the Wrestlers, and have Killia kill the Wrestler at enemy Base Panel.
Should take 3 turns to clear.
(Armor Knight manipulation?)

Get into Revenge Mode ASAP. Activate Overload. Kill a few Horsemen nearby with Killia's first move. Squad Attack a mage to kill 6 units. 
Summon Netherworld to stop reinforcements. Head to boss and Hellfire Shot him down. Clean up rest with Hellfire Shot and Spear skills.

Get 2 Warriors out and throw Killia towards Majorita. Hellfire Shot 2 Maids, end turn. Killia should go Revenge.
Activate Overload, Kill Majorita with Avidya Holy Water.
Squad Attack right Zombie group, and defeat last Maid with whatever.
Clean up left Zombie group with Hellfire Shot.

Get into Revenge Mode by sacrificing 3 units (line them all up two spaces ahead of the Base Panel) and activate Killia's Overload, Hellfire Shot the Succubi until there are no more units where they were.
Squad Attack nearest enemy to trigger final Armor Knight and hopefully kill the brown Succubus.
Summon Netherworld to eliminate reinforcements.
Clean up rest of enemies. Use Spear skills on Succubi, Exploding Tiger on Orcs/Boars, and Hellfire Shot on rest.

Move Killia forward and deploy 3 sacrifices. When Killia is in Revenge Mode, go straight for Bloodis. Avidya Holy Water him twice, then Squad Attack him.

***********Episode 16***********
Inner Dark Demise

Buy Grasida (spear) and Death's Grip (fist)

Normal attack nearest Sage. Stay within the area where the first Sage was and attack other enemies there with Exploding Tiger. Revenge Mode and Squad Attack Dark Knight (target the one with a Chimera in the squad).
Activate Overload and poke Sages.

Move Killia up 5 spaces. Deploy 2-3 sacrifices. Hit the left Horseman with Hellfire Shot. Should get Revenge Mode on 2nd turn. Move Killia up 3 right 1, Squad Attack the nearest Sage and end turn. Activate Overload, Hellfire Shot the Pirates, Exploding Tiger the Dark Knights. 
Equip Windblade War Axe and use Thousand Piercings on Horsemen

Move up 5 first turn, Move up 3, right 1 on 2nd turn

Swap Windblade War Axe with Death's Grip.
Head towards the area with Majorita, using Eclairs to shrug off damage from the Sages. Get into Revenge Mode, Overload, and Squad Attack the enemies there. Use Macrocosm to defeat Majorita. Clean up other enemies in red area with Phoenix Valor.
Destroy No Entry Geo Symbol with Phoenix Valor and defeat the Sages with Thousand Piercings.

Make a tower of 4 units and throw it towards Void. Throw the Horseman away from Void Dark, and kill Void via Overload and Macrocosm (make fist main weapon before doing so). Clean up other enemies using whatever deals the most damage.
Spear skills on Sages, Exploding Tiger on Twin Dragons, Hellfire Shot on Pirates.
(Is it better to have Killia in the middle of the tower?)

Braveheart Killia with Usalia, move Killia forward. Retreat Usalia next turn. Use Macrocosm on the Bits until Killia enters Revenge Mode. Squad Attack the Bits. Do not activate Overload yet. 
Once the Bits are all gone, Use sacrifices to get Killia into Revenge Mode ASAP, activate Overload, Braveheart Killia, and use Macrocosm on the boss from behind. Keep using Macrocosm until she dies.