Ultima: The Mutant Crisis

In this idea for an Ultima fanfic, Magneto and his mutant hordes of the Acolytes have begun a campaign of mutant liberation by violent means across the universe. Professor X fears that this may lead to the Organization getting involved as well, and so he calls upon the Society and the Avengers to take down the evil forces from both sides. But all the while, the amount of heroes on the team begins to wear down their effectiveness at taking down even a single supervillain.

The solution to this problem? Begin forging Avenger-X-Men hybrid teams to take down the Acolytes and Organization one at a time in groups. Professot X and the High Council feel that through this method, they will be able to restore mutant-human relationships to good terms after the disasters involving the constantly threatening force of the Dark Phoenix Aliens.

But all while this conflict is going on, a strange being begins to make himself known in secret in the battlefield. It is a very disturbed canine individual from another planet whose very personality constantly shifts between neutral good and insane evil, and who is constantly jabbering to himself about "dogs over humans, dogs over humans, all hail Sirius...hee hee..."