if you got him at a lfs you could take him back and exchange for another . theres that saying each individual fish has its own personality or aggressivness but i think buttikoferi sets the standard for that rule. my guess is half the butti owners on here keep them with not much trouble with other cichlids while the other half are killers. i have one with many fish see my sig below. sounds like you got a killer on your hands.
Butti's get LOCO! I had one for about 6 months and after 2-3 tanks, he had to go. I couldn't afford to keep a 6" fish in a tank all by himself. They are like Pitbulls