Green Lantern (Comic Book)

Green Lantern is a long-running series of comic books published by DC Comics. Created in 1940, and reintroduced by DC in 1959, Green Lantern is a superhero who derives his power from a ring that grants him superhuman powers. Over the years, multiple characters have taken on the role of Green Lantern. The 1959 reboot also introduced the Green Lantern Corps, revealing that Earth's Green Lantern was part of a much larger intergalactic organization of heroes with similar rings and powers.

A Kind of Loving, a Way of Death (Volume 2, Number 78)
Black Canary falls under the hypnotic sway of Joshua, a cult leader. He programs her to kill Green Arrow. When the time comes to pull the trigger, she can't bring herself to do it. She is freed from Joshua's control when he kills himself.