This. Is. It. I won't put the Boss Strategy under the Boss Guide, but I'll instead put it here.
Stats:
Hit Points: 10,000. Magic Points: 540. Skill Level: 7. Strength: 180. Number Of Hits: 8. Hit %: 100. Attack Effect: Blood Suck. Defence: 210. Number Of Blocks: 1. Evade %: 80. Number Of Magic Blocks: 16. Magic Evade %: 70. Special Attacks: Blind 16, Curse 16, Dispel 16, Flare 16, Meteor 10, Slow 16. Cowardice: 0. Race: Earth, Flying. Weakness: None. Resistance: Bolt, Fire, Holy, Ice, Paralysis, Poison. Absorb: Death, Swap. Drops: None.
Strategy 1: Use the Blood Sword(s). Watch how fast he dies. Simple as that.
Strategy 2: Ok, the legit way to fighting him is basically, since he's immune to most Magic and he has a SHITLOAD of insanely powerful spells on his side, you'll really have to test your limits here. Ultima and Flare sound good right about now for your Magic Users and everyone else can just attack to the best of their ability. Just make sure to heal up when needed and don't use the Elixirs unless your Magic Users run out of MP. Also, when he actually attacks, he'll heal himself with the damage he does to you, which is a pain in the ass, since your attacks deal so little to him in the first place. Just keep your assault up and you'll triumph this long and enduring Battle.
See, wasn't all that training worth it? Heh.
Congratulations! You've just completed Final Fantasy II! Now sit back and enjoy the ending!