basicly it depends on your fish's attitude but probably you wont be able to put anything in with your midevil. I also have a 6-7" midevil in a 75 gallon and she will attack anything that i put into the tank with her except a little tiger botia that is in with her lol. so you could try a small aggressive bottom feeder fish. i tried to put a jack dempsey that I rescued from a 10 gallon tank in with my midevil but she just tore the crap out of him. so i have the tank divided now and i am trying to rehome the jack dempsey.I have a lone 5" midevil in a 75 gallon. The tank looks so empty and I was wondering if anything could be kept with him/her?