Who would win, Joker vs Professor X?
Upon first glance of this question I immediately thought Proffessor X due to his sheer mental power. He could shutdown jokers mind in moments if he so chose, although his morals may briefly get in the way.However thinking back to an incident when he came across Deadpool in “Deadpool kills the Marvel Universe” DP got him to look inside his mind and although not made clear what he sees (most assume it's the secret that they are all characters in a comic book) he has a full mental break and dies.Joker has also been seen to use 4th wall breaks and address us as an audience to him. This could mean joker knows he is just a character too, and this could break Xavier the same way Deadpools revelation did.So in summary sheer power, Xavier wins.But depending on writer and whether joker has 4th wall breaking powers or not then Xavier may die
Why did Deadpool kill all the superheroes?
Following the “Deadpool Kills the Marvel Universe” story line, we know that Deadpool realizes that he is nothing but a fictional character meant to bend according to an author’s will. This dawn of reality irks Wade Wilson.Wade’s eyes have opened to see his reality, to see the world around him the way we, the readers of the comic book do. During his killing spree, he is able to see Marvel character’s such as The Watcher, a character who usually narrates the story to the reader and is considered invisible according to the comic characters (An exception being Marvel’s “Original Sin” story line, where The Watcher is seen and killed by Nick Fury ). Deadpool decapitates him.According to Deadpool, he is doing a favor to the characters of the Marvel Universe and setting them free from the clutches of the author. At one point during the story arc, Professor X (Charles Xavier) looks into Wade’s mind and sees the truth behind Wade’s actions, this totally shocks Professor X and thus results in him going brain dead. At the end of the comic, Deadpool travels to our universe (basically, the universe where the authors and illustrators are making the very comic), and kills the employees of Marvel working on the very comic.In another story arc (Deadpool: Killustrated), Deadpool realizes that the characters keep coming back alive and well because of Marvel’s authors. But I guess that’s a story for another day!!!