The X-Men and the Brotherhood battle each other in a summer camp .
The X-Men and the Brotherhood must cooperate when a large and unstoppable mutant named Cain Marko ( Juggernaut ) threatens both Charles Xavier and Mystique .
The X-Men and the Brotherhood battle each other in a summer camp , but must cooperate when a large and unstoppable mutant named Cain Marko ( Juggernaut ) threatens both Charles Xavier and Mystique .