I must preserve mutant kind, but you can leave

Most of your allies have enter play effects, like Cyclops, Beak, Caliban, Beast, Hope Summers and Marrow, and with Children of the Atom you can easily replay them with Mutant Mayhem. Utopia is insane as magneto gets big stats from Magneto's Armor. Uncanny X-Men is just insane, and playing your allies from hand with resources is also fine, because of this card, and a health boost for your allies is always nice.

The Power in All of Us is really good, especially for Marrow. She is X-force, and children of the atom matters when the ally is in play, so she does not get the discount from Uncanny X-Force. Colossus costs 2 with Uncanny X-Men, which is insane, but also is perfect for The Power in All of Us. You have a ton of economy with The X-Jet and Deft Focus for your signatur events like Metal Shards, Magnetic Missile (which becomes free with Deft Focus!), and Electromagnetic Blast.

If you can get Cable out, you can play Call for Backup, defeat it with Cable, draw a card, get (usually) Hope Summers to grab either an event or Magnetic Bubble, and you have built an insane amount.