I’ve had good success with demasoni as long as you are ready to rehome one or two. I have them mixed with Yellow Labs, Red Zebras (who are the most aggressive in the tank), Perlimutt mbuna (who are also labs, but look completely different) , Hara Zebra Gallireya Reef, Snow White Albino Mbuna (socolofi) and you NEED a bunch of yellowtail “Acei” which are beautiful, chill and school all over the tank in a really cool way.
Those species all look very different from each other. Only the labs and the zebras seem to cross breed, but they don’t chase each other.

 

Demasoni are a difficult fish to keep so make sure you are more stubborn than the fish and determined.

In a 48x18 tank I like 15 demasoni...no fewer. And no other blue barred fish, including the hara. I did try them with demasoni thinking they look THE MOST unlike demasoni among the blue barred fish. They did not die, but over several years they did not thrive and did no show their best colors and behavior. Once put in a separate tank they were a favorite fish.

Shoot for 3 male demasoni and all the rest female. One male would work, don't try two. Either yellow labs or red zebras work well with them. Socolofi or callainos or acei.

If you want all the groups to spawn, I had success with red zebras and socolofi with demasoni. Some of the less assertive species did not spawn much in the demasoni tank.

 

From limited experience: yellow lab, white lab, cobalt blue zebra, socolofi, yellow tail acei, rusty, red zebra, bumblebee. My demasoni harasses a male long pelvic mdoka (not showing much color) and gets harassed by a SRT hongi (current tank boss).