Garland would probally lose to the mist dragon. But then again from that FMV he would kick dragon's asses.

The pirates would be slaughtered horribly.

All the original fiends definatly. They were just so much cooler.

Bahamut would scrap warmech, I meah megaflare vs nuke? A small firey nuke blast...or a giant explosion of non elemental fire?

Chaos would beat Zeromus though, I mean Chaos would just Cure4 himself when he's abotu to die after kicking Zeromus' ass for a while and then slaughter him when he's at full health.