Catastrophe?

[Firo Volondé]

You might want to get the Celestial Weapons for Break Damage Limit.

Catastrophe is probably the easiest of all the Original Creations. I'd hate to see you get beaten by the others.

Technically, Earth Eater is the easiest, since it's impossible to lose against him (if you use Life after every attack), since all his attacks hit only one person at a time.