Not sure if this has been done before. I remember in the new Excalibur when juggernaut was on the team and was struggle with being in such a weaken condition. He went back to were he became the juggernaut and talk to cyttorak about what happen to him. Long story short Cyttorak told him that he was not who he originally plan on bestowing the power of the juggernaut to, but was his step brother Charles who he wanted to be the juggernaut. So my question is what would it be like if professor x was the juggernaut? how would it have played out? ect.