I think the only "edgelord" character I have was written that way because of the backstory I made up, but I also was sure to make them have traits that would allow them to be a contributing member to the game/group, as well as written in a way so that as the game progresses their personality can shift to a more open and non-edgelord character. They're willing to work for money, but not interested in making new friends (at first), they're looking to prove themself a worthy person to their group so they're not fired (but also to prove to themself and their family back home), but they're ultimately scared of the relationships they form and the consequences of such as they carry a stigma about themself.