I have a severum who's a little bit of a bully towards smaller more skittish fish, however he himself gets bullied by bigger fish which I've had to remove from the tank. So I'm looking for fish who can stand their own to the sev but who won't bully the sev back. Maybe a school of some kind of fish, ones that are confident acting? I don't know what kind that would be but I'm hoping to see some more activity in my tank again and less aggression/bullying behavior. Thanks

If you like schools, you could have a school of barbs and a school of loaches. They tend to get along with severums and they're very active fish.