I think adding the "devil" to its own tank will make it very hard to add another to the tank later on. I vote to add her after adding others and letting them establish themselves in the tank. That may it may not work, but it sounds like you've got the tanks, tank space, and fish to experiment so why not?
After all, experimentation makes for a more experienced hobbyist right?
Hell if you could clone these fish then you could try both, but cloning is a whole new topic that needs its own sub forum so I'll leave that alone lol