So: we've got power that copy ongoing of <i>our</i> cards and opponent's cards ie Mystique, Absorbing Man, Rogue. We've got cards that block ongoing and on reveal effects, ie, Cosmo, Echo; use any combo of these 5 and you lock the board basically.

What I believe we're missing is a card that COPIES OPPONENT'S ON REVEAL cards. I was thinking Cypher, Douglas Ramsey. Omnilingual means he can understand literally any language- written or spoken- which I think translates well to the games' adaptation of powers. If we consider the canon abilities these people have, they didn't translate 1to1, but they're close enough while allowing for creative and logistical liberties.

I tend to favor X-Men when I think of fan-casting, but it doesn't have to be a mutant.