You need more other aggressive cichlids of similar size. I got rid of my Kenyi cause they kept killing the tank mates. It was nothing for me to wake up and find another cichlid with its eyes gouged out.
The kenyi's are gonna beat the crap out of your Demasoni. Africans are really aggressive. I would get rid of the Africans. Unless you plan to do a African setup because africans are only good with other africans. But if you do this your gonna need a bigger tank.