BAMF! should immediately make you think of Nightcrawler, who is being reintroduced in Amazing X-Men, but it could mean anything. The other exciting thing about this image is the name Chris Claremont being attached. He is responsible for many of the best X-Men stories and having him doing an X book of any type is good news. I would imagine this would be a limited series or one shot instead of an ongoing, but we should know soon.
