From what I've seen of the X-Men, they'd be horrified by the sheer amount of people Wolverine's killing in that gameplay segment that got shown off. I know Logan specifically gets alot darker, and of course in his past as Weapon X he killed tons of people, but I'd always thought that joining the X-Men was supposed to be him trying to leave that behind him. And obviously someone like him would still be the first to ditch the no-kill rule if it was regarding a real threat, but in that trailer it was just goons with guns, easily dispatched, and yet every single one of them died rather brutally. And when Jean Grey showed up she just immediately started helping out and setting up for combo kills, with this clearly not being their first rodeo in dealing with these villains. Maybe I'm just not knowledgeable enough about the source material, but from all I do know it just seems needlessly bloodthirsty.