evil things ofc
Probably evil things.

I would smoke marijuana in public, and if a cop came, Kamui that joint, or just Kamui myself if i dont want to deal with them.
Warp my school to the alternate dimension and leave it there to rot.
I would do good!!!! Like if there was about to be an explosion I would stop it with my Kamui or if something was about to fall on someone and if someone was about to be attack I would use itYou must be registered for see images
Stand in the girls changing rooms while staying in ghost mode.(of course i'll wear a mask so no one knows its me).