Colossus the power house beat all except Doc Ock and Scorpion.
Doc Ock Stainless Steel is durable enough to take hits or tore from Colossus Strength. All doc need to do is grab him by his feet and unbalance Colossus.
Scorpion use his acid tail on Colossus to win, end of story.
Scorpion just to quick for Colossus to grab and pound
Molecular acid does, but plain old acid would take too much time to affect him, which would be more than enough time for Pete to take a magnesium bath, and there is still a chance that Scorpion may miss.
I don't see how any or all of these guys would do more than stall Colossus at his current strength level.