10 Comic Book Heroes Betrayed By Their Own Sidekicks
2. Professor X - Cyclops
Professor Xavier and Cyclops didn’t have a traditional hero-sidekick relationship, mostly due to Xavier’s inability to fight alongside his young heroes. Still, Xavier adopted Scott as a child and introduced him to the life of a hero, making the betrayal sting all the same.
During the events of Avengers vs X-men Cyclops finds himself imbued with the cosmic power of The Phoenix Force. At first Cyclops and his team use the power for good, tackling world hunger and creating sustainable energy. But as Jean Grey can attest, where there is a Phoenix Force there is a Dark Phoenix.
When Scott inevitably succumbs to The Dark Phoenix, Xavier steps in to stop him. Its then that Cyclops does the unthinkable, and kills his former mentor. Setting Cyclops down a dark path that he never fully recovers from.