Peacemaker
Peacemaker is basically a guy with good intentions trapped in a deeply broken mind. He's obsessed with peace—so obsessed that he'll kill pretty much anyone to achieve it, which obviously defeats the whole purpose. The irony is lost on him.
He's genuinely skilled, too. We're talking expertise with every weapon you can think of. Born killer, trained killer, the kind of person who shouldn't exist but does. What makes him interesting isn't the competence though—it's that contradiction between what he thinks he's doing (saving the world) and what he's actually doing (leaving bodies everywhere).
The guy's got quirks that almost make him endearing if they weren't so weird. He's huge on 80s hair metal, genuinely loves it, and he's got a bald eagle named Eagly who basically functions as his sidekick and emotional support animal. Fans often note that Eagly is probably the most well-adjusted member of any team Peacemaker joins.
So yeah—vainglorious, delusional, but not entirely without heart. His head's just too messed up to let any of that decency actually matter.
Content compiled by AnimeList.moe from publicly available sources.