Nightcrawler is only really playable in an X-Men deck, but he can fill a nice role in the X-Men shell. At a total cost of 4, you get 1 use of a 2 power attack or thwart and a 'block' that returns Nightcrawler to your hand. While it might seem inefficient, consider that is a reactive block that you can save for a massive boost card or surprise overkill or piercing attack. The normal way allies block is proactive, which means you sometimes block only a 2 or 3 power attack that your hero could have just taken. Protective Training makes Kurt a decent thwarting option in an aspect light on options. Other X-Men archetype cards like Danger Room and Utopia turn any average X-Men ally like Kurt into an all-star. In a dedicated X-Men deck, you can feel very comfortable giving a spot to Nightcrawler. If your hero doesn't have the X-Men trait, there is no reason to play this card.
Attack: 2. Thwart: 2.
Interrupt: When an X-MEN character would take any amount of damage from an enemy attack, spend a resource and return Nightcrawler to your hand → prevent all of that damage.
Mutant Genesis #11.
He works fine in any deck. Block with Kurt, then he's an XMen character that's about to take damage, so you can use his ability. — Fry · 159
I guess what I'm saying is that if that's your plan for using Kurt, it's rather inefficient and you should just use a different ally. I suppose lots of the X-Men support cards don't require your identity to be an X-Men, so I guess I should have said I wouldn't run this outside an X-Men archetype — Stretch22 · 252