At the beginning you start out by yourself against Weigraf. Make sure Ramza looks like this:

Weigraf is a big threat due to his large health, damage, and counter ability. Just run away and use potions when necessary, and when ever it is your turn, use accumulate till your strength is 50, yell until your speed is 50 and get your brave to 100. When your strength and speed are at 50, go behind Weigraf and with one lucky strike, you'll defeat him.

But then he turns into Velius...UH-OH! But all you have to do is get near him too and with 2 strikes, he'll be finished, and you'll have conquered the hardest fight of the game.