My two main OCs are literally the first two people to be revived after death, the first became a post human AI who named themselves MARC, they noticed nothing other than him becoming infuriating, the other, was cloned in and got serious PTSD, to the point that getting him through dock airlocks was impossible, although both actively recover somewhat
Trauma can be used to inform character decisions, such as design or personality. I have a character named Rags, and how I drew his face is with hair covering his right eye. He does this because his rival beat him down and gave him a black eye, and ended up enjoying the hairstyle. His personality is a bit cocky and to upshow others, this is because he's neglected in his life by his parents, and to compensate a bit for not being that tall or strong
In dnd it kinda makes sense for trauma, they are then given a reason to fight for what they fight for. My oc making process is more like ripping out a chunk of my soul(give them something i can relate to), and letting it fester into absolute gremlins.