[Zeromus_X]

You get the Apocalypse from beating one of the upgraded dragons, if I remember correctly. It's a new weapon. Although I guess there might be a way of obtaining it that I don't know.

Here's what the new weapons are off the top of my head:

Apocalypse (sword for Terra)
Save the Queen (sword for Celes)
Zorlin Shape (dagger for Locke)
God Hand (knuckle for Sabin)
Longinus (spear for Edgar)
Final Trump (cards for Setzer)
Angel Brush (brush for Relm)
Scorpion's Tail (mace for Gogo. Kill Bill reference?)

I'm sure there's more, but I can't remember right now. I do know that if you want multiple copies of them, you can trade them in at the coliseum (each new weapon can be traded in for another of the weapons).