aaah, I've finally caught up with all there is so far of Ava's Demon.
It begins with showing, yes, Ava and her literal personal demon, who's grown to be intensely frustrated with her - she *needs* her to fulfill a quest for revenge, but Ava's not interested. Until one day, that is, when Ava's forced to enter into a pact with her to avoid dying that day, and both their fates become *much* more tightly entwined..
It does get quite dark at times, much as Wapsi Square can. But the sense of otherworldliness is enthralling. You'll get an idea fairly quickly whether it might be one for you. ^_^
@porsupah I need to catch up on this at some point --- I binged the whole thing in one sitting ages ago, and promptly forgot to actually bookmark or check for updates.