>>716450353It's a matter of philosophy, plus cheerful and grim shit aren't always in opposition. Gallows humour is called so for a reason
As long as it's at least somewhat justified by the setting, it's wholly possible there could be someone using evil powers who still appreciates the concept of a greater good and justifies their dark abilities with some edgy-but-not-angsty philosophy
It'd be a fine line having the other characters accept such a person on their team, but that's been done before too. Vermintide for example is a masterclass in writing characters who loathe the people they're working with but still defend them to the death (Saltzpyre vs. Sienna and Kerillian, and vice versa)
https://www.youtube.com/watch?v=1XUJ_x5DDcI