My way of beating Velius

1.Make Ramza a chemist or mediator.
2.Equip him with a gun.
3.Let him have 'Basic Skill' as secondary and make sure you've learned yell and accumulate, also learn auto-potion and toss all your potions and hi-potions.
4.Equip him with boots with +1 move. (Battle Boots for example)
5.In the battle, move away from Wiegraf and make yell until you have maximum speed. (this will make it so Ramza will have like 6 turns in a row.), after that, accumulate until you have maximum power.
6. Now you can kill him (and Velius) in one blow.

Easy. ;)

The Chemist part is unnecessary. If you have enough movement, you won't need it, so long as you have Auto-Potion with X-Potions. I went in as a Squire with some other class ability equipped which I don't even remember. I actually didn't even need to use the Auto-Potion skill, Two-Swords did the job for me.

Yes I know you don't need a gun or chemist, but It's so funny :D

Well, a gun's damage isn't based on your PA (damage=WP*WP), so using Accumulate is pretty useless if you're using a gun.