WAS DONE ON MY JAPANESE PS2, as far as I know, it does not work on emulator? I don't know, my computer isn't good enough to run a PS2 emulator.
Zaitengraat/Seitengrat, however it's spelled. Finally got one yesterday, and got another one on stream!
May do a LOL playthrough with one sometime for laughs.
Search youtube for the Seitengrat/"Sync Method", which is what I did here and finally got one. vaan1222's video gave me the directions I needed.
Here's the rundown of my 8 abilities and why I had them on:
Null Nerve (voids the Stun and Sleep effects from Vanity)
Mabufudyne (damage to all but the Water Core)
Life Gain (+20% Max HP)
Ice Amp (needed to 1-shot the other cores)
Ice Boost (needed to 1-shot the other cores)
Null Charm (voids the stupid Charm effect from Vanity)
Null Death (voids the Stone effect from Hairava, and the Curse effect from Blood Curse)
Diarahan (healing is good) ----
Whew, quite the battle against this guy. I used up all my Dekaja Rocks (7), and a couple of Soma Drops. There were a few close calls, but as long as I kept my head in the game, I'd be all right.
I brought Debilitate and Tarukaja to have a way to buff myself/debuff BLZbub, for damage/defense and to get him to use Dekunda/Dekaja sometimes.
Beelzebub brought a ruthless ally with him, the Windows Update reboot screen, which got in one last attack after the death of its master.
My plan for this battle works as well as I hoped; Null Mute would prevent Orochi from getting more MP, which allowed me to Debilitate him while Makakaja-ing myself to do a lot of damage with Bufudyne. Resist Phys helped, too.
Thanks to Venfayth for choosing most of the spots to try to attack at the first part of the fight, and thanks to Varin himself for Hunger Wave being totally nullified by having one character in the party.
Also a big thanks to Bufudyne+Ice Amp doing about 9x the damage from attacks, which I was originally going to use on the guy, making the fight take around an hour and a half if that's all I had.