help me plot for Froststone

Okay, so Froststone needs some plotting help. I'm not entirely sure what to do with him. It could be anything pretty much. He's a pureblooded orphan who is kinda cold to new people but warms up eventually type of cat. He's a tad bit shy as well. That's literally bare bones personality. I must make him deeper. Who has ideas! Like he could defend someone and get heavily injured, get bullied by others for some reason, pretty much everything except death and dismemberment/disabilities I'm good with. Doesn't have to be physical, it could be emotional. He could watch someone die that he cares about, so if you need to kill someone off make friends w/ Froststone make him sad. (He's a Young Warrior from Shadowclan)

Have him be Sparkpaw's "cool adult friend", she's a timid, submissive overworker and has a tendency to lose sleep or miss dinner or smthn from trying to get it right.