Iv got 3 different species of Bichir, 2 senegalus, 1 delhezi and 1 ornate. The ornate I find the nicest of the lot. Even though they are all still small at around 5-6 inches
Before I had these I had a male dovii (wolf cichlid) in the tank on his own as he was too agressive to keep with anything else. Tank was 5 foot ( juwel rio 400). I had to rehome him as he outgrew the tank. Iv had numerous other cichlids like dempseys, convicts, jaguars, severums, red devil, red terror, jewel, buttikoferi, oscars... but the dovii was by far the most agressive.
Also used to have 5 red belly piranhas in my 300 litre. That group soon went from 5 down to 1 as the dominant one killed the rest. He was a monster of a fish. Went for me too when I tried to clean his tank