Although Cable usually fits firmly into the hero category, he’s also someone who carries a lot on his shoulders thanks to his rough upbringing in the future and the tragedy he’s witnessed over the years.
Besides, surely there are a lot of you curious to see Michael Shannon ripped and with a cybernetic arm, right?
Looking over his resume, Shannon has a history of playing intense characters, so Cable would be an excellent fit for him.
Shannon would be able to handle Cable’s personality well, being the straight man to Deadpool’s wacky protagonist.