Here is Massacre, a man whose made it his mission to kill every hero and villain he comes across.
Brian Caruso was an ex special forces soldier turned BSH cop, a special division of the police force meant to help take down superpowered threats. He was good at his job and loved the work. He was happy to make a difference in the world. Then his wife was killed in a superhero/supervillain fight. She was caught in the crossfire between Shockwave, an electrically powered villain, and Icon, a vain and arrogant superstrong hero. His wife’s death broke Brian. It made him believe that both heroes and villains are a problem. That their very existence causes them to fight and therefore create collateral damage. So he decided to become the solution. Using his experience, skills, and stolen advanced weaponry, he began a one man war on capes, both good and bad, earning him the moniker Massacre.