Dark Heart

Dark Heart was the chief antagonist of the Care Bears movie and was a powerful but evil dragon (actually his true species was never revealed, it is possible that Dark Heart was actually a demon as he was a regular shape-shifter) that sought to destroy the kingdom of Care-A-Lot along with the Care Bears themselves, like many of the Care Bear villains he is pure evil (at least originally) and despises anything to do with kindness or love and is vulnerable to the Care Bear Stare.

However despite being depicted as evil Dark Heart actually redeemed himself in the end of the movie due to his love for a human girl named Christy, though it took her near-death to awaken the true good inside him.