10 Astonishing Facts About Kryptonite

The DC Extended Universe debuted with the 2013 film, Man of Steel. The movie was heavily criticised for its dark tone, especially for the scene where Superman murders the antagonist, General Zod (which producer, Christopher Nolan, was heavily against). In the scene, Supes makes a snap-decision (literally) and breaks Zod's neck. This scene received a lot of backlash as viewers insisted that Superman would never consciously take a life.

However, Superman killed Zod in the 1988 comic, Superman #22. Not only that, he murdered Zod while he was depowered and unarmed!

In this story, Superman captured Zod and his two allies, and threw them into a cell. Although Zod was imprisoned, he vowed to kill everyone on Earth the second his powers were restored. Superman knew he wasn't bluffing and so, unleashed Kryptonite on Zod and his cohorts. Despite begging for mercy, Superman stood silently, watching them die slowly and painfully. This is considered to be the first time Superman has canonically taken a life.

Superman was so traumatised after he killed Zod, he erected psychological barriers that prevented him from killing.