In recognition of 30 years of X and A books, we get a crossover: Bloodties. In the aftermath of Professor X mindwiping Magneto, Fabian Cortez hides in Genosha and foments a war between its mutants and humans. Yeah, once again, it’s the same storyline.
Beast has been on both teams. He’s the only one.
To protect himself from Magneto (he doesn’t know he’s been mindwiped), Cortez kidnaps Luna, Magnus’ granddaughter, and so Quicksilver, an X-Man and the poppa, and Crystal, an Avenger and the momma, rush in with teammates to save her. But first they talk to Nick Fury, who is really armoring up…
Or at least wearing Flashdance leg warmers.
SHIELD finds itself in conflict with Scarlet Witch, who is trying to protect Luna.
And although Magneto is mindwiped, Exodus wishes to carry on his legacy and also moves in to kill Cortez.
So the teams fight a bunch of genoshans.
Why does it matter? Two reasons, really. First, The Avengers invade a foreign government and so lose favor with the United Nations. Second, the West Coast Avengers break up. On the X-side, there’s no real lasting legacy of these issues other than the apparent death of kinda minor character Fabian Cortez.