Embracing the heel persona
The writing was on the wall in regards to what would happen to each member of The Shield once they went their separate ways: Reigns would be a main event caliber competitor, Ambrose would flourish as a hated heel, and Rollins would thrive as a babyface.
Granted, Reigns did ultimately wind up in the WWE World Championship picture, but Ambrose and Rollins had their spots switched. Ambrose organically got over as a fan favorite in singles competition while Rollins instantly generated heel heat when he joined forces with The Authority.
Although his flashy move set has always painted him as the perennial babyface, he without a doubt found his footing as a vindictive villain almost immediately. His mic work started out slightly shaky, but as he became more comfortable, he embraced his inner jerk and evolved into the best bad guy in the entire organization.