I like Evelynn's quote "I like your style, Kench, but stay out of my territory." This means two things in my opinion.
Demons are territorial and Demons have reputations among themselves.
I don't know if the writers through about these things but the quote definitely suggests it.
So can Demons be friends with each-other? Can they have enemies among themselves? How would demons interact with one another if they bumped into each other? Hostility, friendliness? Curiosity? Maybe in depends on the demon?