Take care to read my rules regarding demons on my O&O page.
demon x human
1. The Hapless Victim
The demon captures, torments, and generally entertains themselves at the expense of the mortal's sanity and wellbeing. As a warning, this sort of role play may include but is not limited to sexual violence, humiliation, bondage and a number of other "fetishes". It will not
include incest, pedophilia or bestiality (as far as unintelligent creatures are concerned). This is not suggested for the light-hearted...
2. The Demon-Slayer
The human is, in fact, a wizard/demon-hunter of no small power going toe-to-toe with all that is evil (if we chose this, then I would suggest the role play focuses on the demon hunter and that whoever is playing the demon also plays all the other characters the demon hunter meets; their superior, their sidekick, their best friend, the romantic interest, the rival, any combination of the aforementioned, etc.)
In this setting, the dominant role could go either way. In any case, a warlock (evil or otherwise), young and somewhat naive or old and practiced, depends on the character, summons a demon to do their bidding (evil or otherwise). The demon, regardless of the warlock's nature, is obviously loathe to do these duties and remains constantly vigilant for a chance to break the warlock's will over them so that they may exact their vengeance. The outcome of this RP can go several ways; the human and the demon can gain mutual, if not grudging, respect for each other. The demon does indeed find a way to escape and does indeed exact its vengeance. Who knows?
demon x demon
Demons aren't nice creatures. Not even to each other. Not much creativity going on in this, but the potential for it exists...
Sometimes, demons do get along. In this case, a demon in a place of power guiding and overseeing the progress of a demon of lower status. Effectively teaching them how to be epitomes of greed, lust, wrath, and every other sin. All at the same time.