What kind of mean? Like chase your finger mean, Or kill everything in the tank, Or just a bang up tough guy personality.
Flowerhorns cover all the basis, But there are many CA cichlids with similar aggression and personality. Usually all fish will be different in temperment and wont be big agro monsters until reaching adulthood, 2-3+yrs. There are alot of factors to rule in, But interbreeding random fish for their aggression isnt going to produce what you would like it to. Dont think you can breed 2 fish to make an absolutely fearless killing machine.