I currently have only one Blue Diamond adult (Bobo the Terror) and one mixed juvenile (Copper). Bobo was the runt when I first got him 5 years ago and he refused to eat for the longest time; allowing his two Snakeskin tankmates to gobble it all up. Then one day he just perked up, started eating all the food
and chasing the Snakeskins away from it. Unfortunately, I did not have a backup tank at the time and despite my best efforts the Snakeskins stressed out and perished.
Recently, we decided to try adding another pair of discus in the vain hope that Bobo had mellowed. The two juveniles (Copper and Sweeny) did well at first, but it was starting to look like we had another Bobo as Sweeny liked to bully Copper around. Then at some point Copper seemed to get sick of it all and started turning the tables on Sweeny. Neither fish seemed super stressed and both were eating, but we found Sweeny dead one morning with no outward signs of disease or trauma. Copper seems to have no issues with Bobo, even when Bobo is feeling like a jerk, probably because Copper was used to it with Sweeny.
I've kept discus since I was a kid (usually 4-5 at a time), but I've never had one that was quite as big a jerk as Bobo.
Speaking of the devil, this is a picture thread, ain't it?
Bobo the Blue Diamond:
Copper the juvenile mix: