Sounds like you got a brute lol. Mine is HUUUUGE, I have never even seen one in real life as big as mine, but he hasnt eaten any of my fish. I have him in a 72g bowfront with a Decorated Goby, Valentini Puffah, Flame Angel, Blue Devil Damsel, and a Fuzzy Dwarf Lion. I have seen the CBS take a swipe at the Damsel before, but he cant catch him.
You should try hand-feeding your CBS. Its probably not fed enough, and it could be starved N hungry, which would explain why it is resorting to eatin tha fishies. I have a homemade "feeder"...its a piece of clear acrylic with a fork at the end and it holds a piece of krill or silverside, etc., and I just lower it down to the CBS and he pulls the food out.