I have a two ideas for some freak models, as well as stats for said freaks in the game mode.
1: Bob: would be a smaller player controlled version of the disciplinary bread we all know and love. His speed would be the equivalent of a heavy, and his special ability would scare all players in a close radius,apply self aware beauty marks, and bleeding to them.
2: The AI: It would be a giant robot heavy, all killed players become robot scouts bound to the batsaber(like the plague doctor). To hunt down living players. Once those robot players die, they are gone for good. The AI's special ability would just outline all players for a couple of seconds(so he could see where they are hiding), and give him increased speed to hunt them down.