All through out the game, Sephiroth has been on your side being a SOLDIER, but wait, that's not the Sephiroth we once knew in the original FFVII. So, it's now time for Sephiroth to turn the bad-ass enemy we all knew. And prepare yourself for the start of this game's succeeding tough battles with level bosses before the final boss. Sephiroth as a starter is not a walk-in-the-park battle for Zack. You need to beat him in two rounds. First, a Level 36 Sephiroth with around 52,000+ HP. This is one of the coolest boss battles in the game, yet just as tough. Do the usual protective measures on Zack - Barrier, MBarrier and to be sure, if you happen to have plenty of Phoenix Down, cast it at once or save it for later. If you have a good amount of HP for Zack, Sephiroth's attacks can leave you still with some HP. Except for one deadly attack which you should watch out for, the Heartless Angel. This attack can render your character with 1HP. But if you managed to heal at once then resume hacking on him, you're in for a win, for now. I've got two restarts because of this boss fight.