Which of these champions should I rank up to progress in the game?

SpiderWarrior77

I'm in a bit of a pickle here, both of the first two choices aren't ideal to face the collector so I'm just wondering
which of these champions I should rank up first in order to progress through the game in general.

Omega Red is sig level: 50

Mr Fantastic is sig level 30

SpiderWarrior77

My bad Omega is sig 20.