
#1 is right dude, the whole premise of the show is the protagonist decides to make the world better by killing people, and goes down the slippery slope into being a villain. It goes from him killing people that actually deserve it to him killing people for being lazy. One person shouldn’t be trusted with the power to make people live or die.
Do you really think that you wont be changed by all that power? You really think you can handle the ability to kill in a whim without being tainted? Do you really think you’d be careful enough to not get caught? It’s a fun fantasy to think about but you’d have to be profoundly arrogant and stupid to think that power should belong in anyone’s hands let alone your own.