Yeah, it's a pretty standard L-Zeto victory. Buuut, this is actually the Ultimate Challenge. And let me tell you, Zeru did NOT pull any punches with this. This is old-school, Etrian Odyssey-style difficulty RIGHT HERE.
You know the L-Zeto battle? The one Ninja wrote a guide on? It's that, except Zeto gets his whole party out in THREE TURNS.
It's as unfair as it sounds. Eight 300000+ HP characters on the field in 3 turns. Now THAT is stupid.
Time to document my strategy.
Silly me. I forgot to write down the prerequisites.
A. You must have beaten the main storyline. (Hein final form + good ending)
B. You must have attained all ten elemental stars (Yes, including Nayu and Mel's)
C. You must have completed all ten story arcs.
D. You must have found and completed the secret chapter, and defeated Normal Light Zeto, which Ninja wrote a very nice guide on here.
14 RBs on all characters. This should be expected, really. Max stats for everybody.
All Transformation skills on all characters
Soul weapons on all characters (or at least the ones you're going to use)
Elemental Abyssal Armors on all characters you're going to use.
5+ Fried Furious Fish
5+ Cooked Lobster
5+ Tuna Soup
Lots of patience
Lots of luck
You need some pre-battle preps first. My team setup was....well, the picture up there shows you.
First, get your team to 100% SR. Next, go to the training zone in the map and get into a random battle. Trans all four of your characters, then on the next turn, use defend all four of your characters. The first character on turn 3 uses Escape. Use a Cooked Lobster on Melody and Zeru, save, and EN GARDE!
Let's crunch some numbers, shall we?
TURN 0: Light Zeto (350,000 HP)
~ Luminous Strike
~ Holy Soul Impact
~ Radiant Slash
~ Seven Slashes of the Light Dragon
~ Uroboros Guard
~ Beam of Light
~ Soul Resurrection
Analysis: Big boy Zeto here has the most stats out of any enemy in this battle, and a massive movelist to boot. Not only that, his Seven Slashes is a guaranteed OHKO without any defense or Light resistance, which is why I brought the team above. Fortunately, he carries a 200% weakness to Dark, meaning Melody can walk all over him after two boosts. Look out for his Seven slashes and Radiant Slash. The rest of his other moves aren't nearly as threatening.
Right as you enter the battle, you will get to choose moves for your characters. I advise you try to get Nayu to go first so she can cast preemptive Goddess Dark Aura. Zeika needs to cast Immunize ASAP, or you pretty much lose if Ethan gets a freeze against you. Zeru's actions can vary, but Melody should always attack L. Zeto and do a crapton of damage since he's weak to Darkness.
Before you can do anything, though, L. Zeto will instantly use Holy Soul Impact, Radiant Slash, and then Seven Slashes of the Light Dragon, then resurrect Ethan, Luna, and Evelyn. Since your characters are still in a "defend" pose from the previous fight, they'll only take half damage from the onslaught. Also, Zeika, Nayu, and Melody's Abyssal Armors negate 50% of Light damage, so they'll take practically nothing if they get attacked. If Zeru gets hit by all three, you have to reset and try again.
A Lobster+Goddess Dark Aura Crescent Night Slash should do around 150000 ~ 170000 damage against L.Zeto.
Zeru's move depends on when his box shows up. If his action box shows up BEFORE Zeto's onslaught, use Aegis Defense. If it shows up after, you're probably safer using Aegis Defense anyways. If you're feeling lucky, though, you can try for a Radiant Flare against Ethan. Only try this if Zeru is near or at max HP.
ETHAN: (300,000 HP)
~ Calm Wind (sr decrease 50%)
~ Ice Strike
~ Ice Blast
~ Soul Debuff
Analysis: Ever play against Gengar in Pokemon? Did you know that the combination of Focus Blast + Shadow Ball can hit every Pokemon in the metagame for at least neutral damage? Well, this guy is like that. He has only four moves, but these four moves can wreck HAVOC on your team. Debuffing can set up a complete team kill if all eight characters are on the field. His two ice moves ensure that you have to keep Immunize up, or you'll just die. He is your top priority to kill right next to L. Zeto himself. He carries a 200% weakness to Fire, meaning Zeru can 2-3 shot him, which is good.
EVELYN: (300,000 HP)
~ Soul Twin Shot
~ Soul Tornado (~70% HP)
~ Soul Arrow Storm
Analysis: Little blind girl here is extremely dangerous, and you should NOT aim for her first. Soul Tornado is too dangerous to deal with for most of the match, and Evelyn is not your top priority. However, if you don't have any defense up, her arrows are probably one of the last things you'll see before the Game Over screen.
LUNA: (300,000 HP)
~ Soul Spike
~ Monkey Soul Magic
~ Soul Anchor
~ Hydro Soul Cannon
here is ridiculously dangerous without defense, similar to Evelyn. I would almost recommend taking the two of them out first if it weren't for Ethan's Soul Debuff...
She has two extremely powerful Water attacks, and unlike Evelyn, can use Hydro Soul Cannon at whatever HP she pleases! She does craploads of damage even if you do have defenses up. Worst of all, Monkey Soul Magic makes her entire ensemble hit like a truck, so you can't let that happen.
ENEMY TURN 1:
Right off the bat, we have a handful of stupidity shoved in our face. If you didn't use Aegis and the trio goes for Ice Strike + Soul Arrow Storm + Soul Anchor, that's practically Game Over right there.
Ethan is the reason why you NEED Immunize on at ALL TIMES. Without it, a frozen character basically means game over.
If he casts Soul Debuff, you lose your chance to 2HKO L. Zeto and you have to go for the 3HKO with Mel. On the bright side, he won't beat the crap out of you, so be thankful for that.
Luna's Monkey Soul Magic is extremely dangerous. Letting it stay up makes your party take a truckload of damage. You should Liberate it ASAP if it goes up.
ZETO TURN 1:
He shouldn't be a problem...unless he decides to 7 Slash Zeru, in which case just reset. He has Uroboros Guard though, so you need to Liberate that if it goes up.
PLAYER TURN 2:
At this point, HOPEFULLY, you haven't taken too much damage. If Immunize was dispelled, you need to recast it. If that's the case, then you should probably Aegis on Zeru then use a Tuna Soup with Nayu. Melody should continue attacking L. Zeto.
If your team is looking pretty good in the HP department and Immunize+Goddess Dark Aura is still up, then you're in quite a bit of luck for this turn, as this is the best-case scenario. Cast Advanced Nature Blessing on Zeika, then use Radiant Flare on Ethan. Nayu should use Advanced Dark Aura. If she goes before Melody, then Melody can KO L.Zeto with another attack (that does 227k damage!)
ENEMY TURN 2:
See Enemy Turn 1. Just be wary of what happens. If you get Dispelled, you could take a lot of damage.
ZETO TURN 2:
See Zeto Turn 1. If he's dead, then kudos to you!
PLAYER TURN 3:
By this point, you can actually get another turn before Zeto and pals can move, so this is effectively two turns.
Recast any buffs that went down, and grab the KO against Light Zeto. You may need to use Goddess Dark Aura again before trying for a KO, or you may need to heal up with Zeika. Zeika's Party Cure 3 heals all characters to full, so keep that in mind.
PLAYER TURN 4: Finish up whatever you were doing, cast Aegis. If Zeto isn't dead by this point, kill him now. Try to kill Ethan if you can, but don't overextend. The threat of Uroboros going up is too much, along with the monstrous 7 slashes. Brace yourself...
If Zeto is not dead:
ZETO TURN 3: He attacks with whatever, then summons the rest of his team.
ARIA (300,000 HP)
~ Mystic Pillar
~ Party Soul Healing III
~ Soul Liberation
Analysis: She's adorable, but she's also the next threat blocking your way to victory. Her 3 moves actually make her more dangerous, because she's more likely to go for Soul Liberation, which, once again, can result in a Game Over. She also carries a 200% weakness to fire, meaning that Zeru is practically required to beat these ridiculous enemies. Don't worry about Party Soul Healing III-- it's actually a blessing in disguise, as it means she won't dispel your team.
KLAIRE (300,000 HP)
~ Demon Soul Breath
~ Soul Reap
~ Soul Curse
~ Maple Warrior
Analysis: This is it. This is the reason you HAVE to have immunize on ALWAYS. If you get hit with a Soul Curse without Immunize up, then it's almost certainly GG. You'll move slow as crap and take tons of damage from anything, and have your skills sealed. Hope Zeika didn't get cursed. If Zeika DID get cursed...well, bye-bye. If Zeika didn't get cursed, but got stunned from the next character's attack, then you're still dead. Isn't this wonderful? His Maple Warrior also boosts stats similar to Luna's Monkey Soul Magic, so Liberate that crud ASAP.
ELLIS (300,000 HP)
~ Carnival Edge
~ Earth Strike
~ Ground Crush
Analysis: GROUND CRUSH. That thing cost me more games than I can count. It stuns, meaning between Ellis's stun, Klaire's Soul Curse, and Ethan's freeze, you have about a fart's chance in a typhoon of surviving without Immunize. Otherwise, Carnival Strike goes crap-tons of single-target damage, and GROUND CRUSH STUNS TOO.
SILVIE (300,000 HP)
~ Volt Shot
~ Fatal Bolt
~ Soul Arrow Rain
Analysis: Silvie is actually the least of your troubles. Sure, she'll hit like a truck if you don't have defenses up, but she's nice enough to not carry anything too game-changing, except maybe Quicken. But it's not as bad as Uroboros or Maple Warrior or Monkey Soul, so you can leave it up without too many qualms.
Back to the battle. Enemy Turn 4 is a bloody storm of moves flying anywhere. Many things can happen, so I can't really predict the strategy from here on out. Just hope you don't get a game over because Aria Liberated you then Ethan/Ellis/Klaire went to town on your face.
Your top priority from here is Aria, if Ethan's already dead. The moment Aria goes down, you can secure victory, but if not, your life still hangs in the balance. Buff up Zeru and try to get the 2HKO/3HKO without dying miserably. You can shorten the process by attacking Aria with Melody, as Aria also carries a 150% to Darkness.
FINALLY you can take a breather at this point. L. Zeto, Aria, and Ethan are dead; the rest shouldn't be an issue, because between Zeika's Advanced Nature Bless and Zeru's Aegis Defense, you'll be taking 0's everywhere...UNLESS they get up Maple Warrior or Monkey Soul Magic, which you still have to dispel. At this point, I recommend killing Luna and Klaire, as with them dead, your victory is practically secure. Klaire packs a -100% to Darkness, so you'll have to kill him using Zeru. After they're dead, all that's left is Silvie, Ellis, and Evelyn. Evelyn is probably the most dangerous enemy from here on out, so you can kill her or save her for last. Honestly, if you've gotten this far, Zeru's Aegis + Zeika's Advanced Nature Blessing + Immunize can wall them until the cows come home. Just play smart. Your transformations should be disappearing by this point, but no matter; they served their purpose.
This strategy is actually very inconsistent. A lot of it is determined by luck due to the sheer difficulty of the task. If you think there's a better team setup, then just reply to the post~
HOWEVER, I can't use Royke in this battle. Somehow, my Royke was glitched after having not playing FSII for so long, and now he has permanent Goddess Dark Aura and Immunize on him that I can't get rid of!
I've tried killing him, going to inns, winning battles; it doesn't do a thing. So I specifically didn't use him because I knew it's unlikely someone else would have a Godroyke.
Well, I'm done with the game, apparently. But I found a new thing: All of the enemies can be Silenced. It will stop Aria from Liberating and Ethan from Debuffing, and it'll also stop Klaire from Cursing and casting Maple Warrior, and I believe it stops Luna's Monkey Magic as well. Just a thought to throw out there.
After that, you've officially
beat Final Story II, utterly and absolutely. Congratulations.