#4 Seth Rollins
After becoming the face of Monday Night RAW last year, Seth Rollins won the 2019 Royal Rumble and announced to challenge Brock Lesnar for the Universal Championship.
He has the clear babyface in the feud, even getting beaten up by Brock time and again. But then something happened on the RAW before 'Mania, and Seth decided to low-blow Lesnar in order to stand a chance against him.
Now if this wasn't surprising enough, he again low-blowed The Beast at WrestleMania during their match and went on to win the Universal Championship by pinning Lesnar in the middle of the ring.
Now, this new attitude of his is pretty interesting, as he is neither a proper heel nor a standard babyface. All this could change soon as Rollins could shock everyone by turning into a full-fledged heel.
Currently, all the two main men's championship and women's championship are held by 3 babyfaces. If you were to ask me, who amongst the 3 could turn heel to maintain the balance, I'd definitely suggest Seth Rollins.