**EDIT: Medusa and Echantress can no longer be run in this deck. On the other hand, the Beast change means you can now mulligan Rocket and don't have to worry so much about waiting to play Angela.**
Without Mysique this is a platnum tier deck.
That said, it is a particularly good case study in the value of Luke Cage in Cerebro decks.
Unlike C2 & C3, C4 does not have a tool to change locations. However, even more important than protecting from hostile terrain, Cage stops Scorpion, Spiderwoman, [Edit] and High Evolutionary from being deck killers.
Sera's inclusion is something of a given. Most of the deck costs 2, 3, or 4 energy. If you don't have Sera, Klaw is a reasonable claw to run instead.
The last key card is Moon Girl. She is able to at least partially cover for the lack of Mystique if you have your Cerebro on hand. She can also provide fuel for Sera.