Mutant Protector

This deck is built around sneaking in protection and basic X-Men allies into play with Mutant Protectors for a relatively cheap cost.

You'll notice that most of the X-Men allies in this deck have great "enter play" abilities, or come in with a tough to soak up a big attack. Prioritize Colossus, Polaris, Armor & Rockslide for big villain attacks, since they can take the hit and stick around for more activations or blocks. Beak, Forge, Triage, & Professor X are the one hit wonders of the group, and likely won't survive the attack. But their enter play abilities are very strong, and are worth dropping in for the block and either extra threat removal, a support card, healing, confuse, minion stun, or ready.

Utopia can also trigger off of these allies coming into play to block, so work through your defense/exhaust sequencing by having Nightcrawler block the first attack, and use Mutant Protectors on a second villain attack or a minion attack to get Nightcrawler a "ready."

Use Desperate Defense when you're out of Bamf!'s, or you don't have your Armored Vest & Kurt's Cutlasses out yet to boost your defense stat, or blocking for other players in multiplayer. Not Today! is useful to help get rid of pesky side schemes.

Hard to Ignore & Unflappable can help keep a lid on the main scheme, and get you another card after a perfect defense play.

Prioritize The X-Jet to grab Bamf! from your discard pile. Prehensile Tail to play Mutant Protectors and other defense events. Then use Deft Focus to play Nightcrawler's events on his turn.

With all the allies, Bamf!'s and defense events, you shouldn't have to flip down, except in extreme situations. Use a confuse from Professor X, or 'Port Away to go heal, and pop back into hero mode to keep defending.

Always play Teleport Drop when you get the chance when you're playing solo, since Nightcrawler's damage output is pretty low.