Shadowcat Surprise

Shadowcat leans into her ability to flip forms regularly and attack often to supercharge herself using Fluid Motion. With all three in play, plus an array of cheap attack events to trigger it, plus Combat Training and Symbiote Suit if you are so inclined, she can get herself up to seven base attack. With Ready to Rumble and Shadowcat Surprise (her event card) she should have no trouble readying to strike at least twice in a turn. Triggering all three Fluid Motions requires good draws but all of her Aggression events are cheap which helps her play three attack events and potentially have something else to do.

Symbiote Suit, Colossus, and Shadow and Steel are all optional cards for this deck. Shadow and Steel is a good card so worth trying to pull off, which requires Colossus if you're not teaming up with him as a hero. Symbiote Suit gives you that extra attack to pull of seven, but six is still good. The other benefit is the extra hand size which increases the odds of being able to trigger all Fluid Motions in a turn. With multiple ready options she is one who might get enough benefit from it to make the extra Encounter card worth it.