Jack/Raiden - Metal Gear

One of the few examples who actually admit it. His whole ‘arc’ in Metal Gear Rising is about understanding and accepting that every of his acts on the battlefield weren’t just for justice and to defend the weak, but him genuinely enjoying bloodbaths. And that no matter how many goals he achieves nor how many terrorists he stops, he will never be able to walk out of the battlefield and start a normal life

Frank Castle/Punisher - Marvel Comics

I’ll maybe have problems for this one but idc. In most versions, a key idea of his character is that his whole ‘Punisher’ persona is an excuse to feed his personal vendetta. He’s not a badass vigilante who try ro bring justice, he’s a sociopathic murderer who commits atrocities while sometimes trying to reassure himself by saying it’s okay because his victims were worse than him

Light/Kira - Death Note

Despite proclaiming he wants to make the world a better place through his inescapable justice, it’s not hard to understand he’s just a teen with a god complex who just wants to feel feared and all-mighty. Quickly after starting his war against criminals, just in the 2nd chapter he already kills someone who he thinks is L (so not a criminal, just a detective) just because 1. He criticised Kira on television, and 2. Light wanted to show off how powerful he was

The “good guy” just enjoy killing people