I have been feeling unmotivated to write recently and been and still am busy Irl, so here's some ideas-

Revolutionary war against Arctic Empire, but Tommy is part of the revolution and doesn't know he's Phil's son, but his family knows

Tommy somehow meets SBI gets adopted by a Mafia Boss, Dream, and starts a mafia war before being adopted by SBI

Tommy somehow keeps escaping vampire SBI without knowing their vampires, SBI go from annoyed, to bored, to adopting.

(Not dark, but-) TikToker Tommy and SBI learn he uses TikTok, chaos ensues

Something happens and Tommy gets blamed for a crime and is put in jail for x amount of time, Mafia SBI break their little brother out and are forced to introduce him into the mafia world