The Final Day
After the opening cutscene, Lightning will be standing just outside the Cathedral doors. Before you do anything, be sure to speak to the merchants nearby! It will be one of your last few chances to purchase Weapons, Garbs, synthesize Sorcery, and upgrade Abilities.
Once you're prepped and ready, approach the double doors to face off against some guards. These guards mostly wield physical attacks, so confront them with a strong physical Sentinel and two attackers. They're equally vulnerable to all elemental magics. From there, enter the cathedral and approach the altar to trigger a cutscene with Noel.
Note that since there is no more time, there's no longer any penalty for running away from random encounters. Only fleeing scripted battles that exist as part of a cutscene have any ill effect, and those simply boot you back to the beginning of a scene.
Once you reach the lower depths of the cathedral, team up with Fang to defeat the Chimera. For an easy victory, use one physical proof and one magic proof sentinel build and a third attacker form, and help Fang deal damage with Deprotect Hunter.
MISSION NOTE: FUN WITH FANG
After defeating the Chimera, Fang will join up with you, but if you immediately enter the doors to God's Sanctum, Fang will automatically be out! Before entering the doors, take advantage of Fang's fighting abilities to help you farm for enemies, especially if you are aiming to spawn the Last Ones for the Arcangeli, Sugriva, and Chimera.
If you prefer NOT to spawn the Omega versions of the last three enemies, then enter the doorway to trigger a lengthy cutscene.
OPTIONAL MISSIONS: COMPLETE THE FOUR TRIALS
While it isn't mandatory to complete the four trials, you will miss out on a sweet weapon if you don't do it. There are four doors inside the Sanctum and each one has FOUR floors filled with strong enemies. After clearing three of the floors of enemies (Chimera, Arcangeli, etc), the fourth floor will contain a supply Sphere with a special Magic ability!
- ALTAR OF SALVATION - Flare Lvl 1
- ALTAR OF JUDGEMENT - Chill Lvl 1
- ALTAR OF BIRTH - Tornado Lvl 1
- ALTAR OF ATONEMENT - SURGE Lvl 1
After completing all four floors, jump down to the Sanctum and approaching the glowing orb at the altar to receive the Ultima Weapon! From this point, you can continue farming enemies to spawn the Omegas or speak to Mog and fill up on any X-Potions, Regens, Hastes.
Once you're prepped and ready to go, enter the doors near Mog and be ready for the last battle! After the cutscene, walk up the Sanct of Theogenesis and approach Bhunivelze to begin the epic battle.
BOSS BATTLE: BHUNIVELZE
God loves to throw powerful Magic attacks and isn't much of a physical attacker. That being said, you'll need a Schemata that can resist lots of Magic (mainly Aero and Fira).
Part 1
In this form, Bhunivelze will use many fairly low damage attacks that are pretty easy to read and block. Skills like Auraga which can damage the boss while you're guarding are helpful for keeping up damage. Half way through, Bhunivelze will cast Haste and start casting Giga-Graviton and Ruinga in quick succession. Keep the same strategy and burn down the boss quickly.
Bhunivelze will also use debrave and defaith, which lower your attack and spirit respectively. While taking something to make yourself immune to this might help, there are no other negative status effect in any of the other forms. Take the hit and burn him quick.
Hint: if you are not able to burn down the boss before dying to doom or need to use items, you likely will not be able to beat the next three stages of the battle. Ensure you have Lightning's Ultima Weapon and are keeping up damage between Bhunivelze's attacks.
Part 2
Bhunivelze will start swapping elemental forms, making him immune to that element and start casting spells of that element. Fire form is the best for dealing damage as you only need to block one burst of damage and then can attack again. Aero is by far the worst as skills like Auraga and Tornado are much longer spells that you need to block the entire time for or you'll be thrown into the air. As long as you have two different element spells, this shouldn't be a problem. While a lot of these spells are powerful, taking a schema with a lot of magic defense can completely nullify most of this section.
Bhunivelze will summon Monads with Monad Beget, which are small attackable orbs that he will blow up later on with Wings of Destruction. If all three are left alive when he uses Wings of Destruction, each one will deal ~1,500 damage plus ~1,500 from Bhunivelze himself (~6,000 total). Skills at the -ara and -aga level and Blitz will make sort work of them. Keep your eye on Bhunivelze and block his attacks while attacking them. It's easy to take a good 4.5k damage from Bhunivelze regular attacks in an attempt to not take 4.5k damage from the Monads.
After the first 50% of health, Bhunivelze will start using Genethliac Hymn, which causes small packets of lightning damage all over the stage. The lightning damage can mostly be ignored. If you are able to stagger Bhunivelze during this attack, he will use Falling Star instead of Dancing Mad. Dancing Mad does significantly more damage than Falling Star, so it's worth taking skills that will stagger him more effectively. It's not uncommon for him to follow up that attack (within a few spells) with Wings of Destruction, so heal up quickly to at least ~1,500 hp.
Part 3
Bhunivelze will start casting Holy Blade after a approximately five bouts of attacks. Every Holy Blade makes him stronger and increases the number off attacks in each chain. Make sure you block every single on of these. These attack can throw you in the air and really set you back. There isn't much time between these attacks to get damage in and being throw in the air basically wastes that time.
Also make sure you are extremely aggressive while the number of Holy Blades used is low. It gets much more risky to attack the later into the fight you get.
After he uses Holy Blade three times, he will end with Hypernova. This skill is absolutely devastating. It will lock you out of your skills (you can't guard it) and deal ~6.6k damage to you. There is no tell besides the fact that he will use it on the third Holy Blade approximately 5-7 attack chains in. It's not a bad idea to try to burst through this section as fast as possible. Stagger him and use some EP to burn him fast. Don't use all of it. You'll need some for part four.
Part 4
In this section, you need to stagger Bhunivelze and burn him quickly. Check to make sure you have at least one skill with a Stagger Time rating of A or B and a skill with a Stagger Power rating of A or B. There are small moments during attacks when he is vulnerable to be staggered. Use your EP to take advantage of these small moments as they go by extremely quickly.
Be careful with melee attacks. Bhunivelze's head is very high up so if an attack start charging while you're in the air, there's a good chance you won't be back on the ground in time to block it. Don't get greedy if you aren't overpowered.
Bhunivelze will use a skill called Heartless Angel where two angles circle you and laugh. After about ten seconds, they will do a small air like animation at Lightning's feet (doing nothing) and then immediately use their ability, reducing your health to 1. The camera will zoom in really close to Lightning when this is about to happen. That's the time to block this. For those ten seconds, the boss will completely idle and for a good 5 seconds afterwards as well. This is the perfect time to increase your stagger as much as possible.
Overall Strategy
- Stagger Skills - Make sure you have one skill with a high stagger power and another with high stagger time.
- Area of Effect Skills - Monads are low health enemies that need to be burned quickly. Bring Blitz or powerful AoE magic.
- Magic Defense - Most of the skills Bhunivelze uses are magic based. Having high magic defense can completely nullify a lot of the skills he uses.
- High Health - Some skills just do lots of damage and there's no good way to reduce them. Hypernova is going to do ~6.7k damage and no guarding or damage reduction is going to stop that. At least one schema should have significantly more health than that.
- Strong Guards - Lots of the later parts deal lots of damage even while guarding. Every little bit more damage you reduce is another item you don't need to waste.
MISSION NOTE: THE BAD ENDING
If you end up losing to God due to some inferior battle skills or under-powered Schemata, you'll be treated with a super-quick ending and you'll be sent back to Day 1 (New Game+ will NOT be unlocked).
Congratulations, you completed Lightning Returns! Enjoy the Happy Ending.