All right, I'm finally at the point. Let's go with the actual tactics.
First of all, Hyakki is immune both to Fire and Ice magic. Wind magic "seems" to deal some damage but still not even remotely enough to bring her down. So, there are two valid options:
- Edge Dagger - deals 100 damage in stock, 300 when crits, will do 110 on crit after the next update.
- Psi Volt Tackle - deals 150 damage, has a 5% chance to stun Hyakki for one turn. Before you ask, yes, there is a chance to stunlock her for entire fight, here's the number:
(2,8574684782056874555394588707634 * 10 ^ -435)%
Meaning, you'll need roughly
6,6582974879239327986986369166441 * 10 ^ 430 years to see that outcome. Neat.
Unfortunately, no human would last that long, so let's get down to equipment.
- Weapon: Edge Dagger. Of course, since there is no MTTK nor MIRV (MMTK would, actually, be weaker than the dagger anyway, and MIRV is a post-game weapon).
- Offhand: Scaly Shield (if you're going defensive) or Ether Glove (if you're sticking with Psi Volt Tackle).
- Accessory: I WANT TO SCREAM "SKULL COAT", but no, Mystery Cream. Else the Lust gain will be too high to handle.
Now, to skills:
- Personally, I prefer Psi Volt Tackle approach, so: Vitality UP MAX, Magic UP MAX, Agility UP MAX, Vitality Regeneration, Magic Evasion.
- If you want to try going Physical way, Willpower UP MAX, Attack UP MAX, Agility UP MAX, Willpower Regeneration and Physical Evasion.
Note, however, that Magical Evasion gives you 30% chance, while Physical Evasion gives 10%.
Spells:
- Hell Break, since you need to keep Willpower high enough, else Hyakki would eventually finish Kazuya off. Guess that was made to counter Frozen approach I used before, see my previously recorded battle with her.
- Frozen (instead of HB) - will make Hyakki's moves even more bearable. Unfortunately, you'll have to come up with other way to constantly (at least, once per five turns) keep your Willpower above 50%.
- Since 195 SP is all that's given, there is no way to get BOTH Hell Break and Frozen, unfortunately. Gotta stick with one.
- Psi Volt Tackle, if you're going Mage route.
- Sylph Storm, keep it active at all times (same as Hell Break / Frozen).
And that's about it. With that set it should be possible to withstand her attacks and deal her damage up to the point when she starts to heal herself. Will update the post / make another one once I have a proper way to beat her past that.