Coral beauty at it again

A couple of months ago I posted about my coral beauty that killed a royal gramma. Well, he's at it again. I had a couple of firefish that died in a white spot problem after I left on vacation. The coral beauty survived. The problem was solved, and I got two more firefish. However, the coral beauty seems to have become aggressive towards them. They've only been in a week and the aggression started a couple of days ago. He isn't aggressive towards the two banaggi cardinals that also inhabit the tank. I can't net the fish out because there is around 100 lbs of live rock that I can't move in the tank that they hide in.
I am at a stalemate. If anyone reads this and has a solution that does not involve moving rock or killing fish, that would be fantastic. The aquarium in question is 120 gallons.