Sabertooth
agent zero
deadpool
Mavrick
vsCyclops
cannonball
Collosuss
Bishop
Beast
Archangel
Ahem...
If AZ's adamantium rounds can damage colossus, agent zero it is.
If not, Colossus won't be taken out.
Also, Cannonball. I'm pretty sure he can absorb kinetic beams of AZ, and he is invulnerable to anybody else.