#4: Dean Ambrose: Two-Face
Most people would assume that Dean Ambrose and the Joker are perfect matches.
While it's true that they are both seen as mentally unstable manipulators, I went a different direction for Dean. Two-Face used to be Batman's friend when he was simply District Attorney Harvey Dent and Batman was merely beginning his crusade against the corrupt.
But after a traumatic experience where acid was thrown in his face, Dent's psyche fractured into two parts - the stable Dent half and the unstable, driven by chance Two-Face part.
Dean was always a trusted ally of his friend, Roman Reigns, but when the latter had to temporarily 'leave' the WWE in order to deal with his leukaemia, Dean lost it.
He turned on his other friend, Seth Rollins, later in the same night Roman left his belt in the middle of the ring. Dean and the Shield terrorized the WWE when they first joined the main roster, but he's been a villain for the first time as a singles' wrestler.
And ever since Roman has left, Dean has done nothing but torment his former friends. At first, he mocked Roman, saying he'd have to pay for his sins.
But since he's around, Rollins has suffered the brunt of Dean's malice. Like Rollins, Batman has faced the majority of hate spewed by Two-Face ever since Dent transformed.
Two-Face often blames Bruce for things in his life and Bruce does feel guilty for what happened to his one-time friend. He still believes that Harvey can be reasoned with and always considers him a friend despite his villainous deeds.
Dean, Roman and Rollins will always fight together and fight one another. They'll always be linked together due to their beginnings in the Shield. Sometimes your greatest friends become your worst enemies.