Fan Casting Post-Credits Scene in The X-Men: Mutant Academy

In the post-apocalypse future, the mutants and the humans who help them are slaughtered by powerful robots named Sentinels. Professor Xavier, Magneto, and his friends meet at a monastery in San Francisco and Xavier explains that the invincible Sentinels were created using the DNA of Mystique that was captured in 1973 when she tried to assassinate their creator Dr. Bolivar Trask.