SLOT Six: The Team's OH SHIT button
All out baby. The Big Gun. The only things that are going to be illegial in this category are cosmic level force of nature entities like Galactus, Q (Star Trek), The Living Tribunal, The Phoenix Force, etc.
Examples: Thor, Super Man, Shazam, Silver Surfer, Magneto, Doctor Strange ... Go big or Go Home
I have a feeling that people are going to pick a version of Superman for their team.
Also, let’s just hope that we don’t get a Superman vs Goku match out of this.