For most of his 84-year history in various media, Superman has been defined by the restraint he employs while using his incredible abilities in combat. It has been made clear that the Man of Steel is frightened by the consequences of him losing control and/or wilfully lowering his inhibitions in life-or-death situations.
Ultimately, this is why most versions of the comics icon have ‘no-kill rules’ while engaging villains from Earth and beyond. However, there have been instances where the Last Son of Krypton’s aversion to killing has been put to the test. The outcome and intent of these moments depend on the continuity/writer’s intent, and consequently, good ol’ Supes has taken some lives in the heat of battle.
Some of these instances were last-ditch efforts done by a desperate Clark, while others were bloodthirsty acts that signaled or reinforced his descent into darkness. The latter in particular is a terrifying prospect due to the devastating power the hero wields, as well as his unrelenting optimism being replaced with a ruthless, violent edge.
While the denizens of Metropolis are lucky that their guardian angel normally exercises restraint during his heroic exploits, some of the instances on this list the devastating consequences a murderous Superman would cause.
10. Doomsday -The Death Of Superman
Kicking things off with the most well-known instance of a Super-murder, the Kryptonian monster’s death also resulted in the iconic hero biting the dust as well (though their respective deaths were not as definitive as is expected in the realm of comics). Following his escape from his underground tomb, Doomsday went on a destructive rampage throughout the country that eventually attracted the Justice League’s attention.
After a brief but violent encounter with the behemoth, only Clark was left standing to face the new and powerful threat. Doomsday’s animalistic rage and sheer might forced the hero to tap into reserves of power he had previously held back just to keep up with his opponent, and naturally this display of strength proved to be dangerous for both combatants as well as the various environments they clashed in.
While the Man of Steel was able to put down the threat before it escalated any further, it came at the expense of his own life. Subsequent encounters with the monster have seen the hero win by the skin of his teeth due to Doomsday's terrifying regenerative/adaptative abilities.