Demons

The lower souls of the Yozis are called Demons now. Thanks to the terms of the Yozis' surrender, they can be summoned into Creation and ordered around. This is difficult for mortal occultists, since Demons can be very willful, but prepared Exalted sorcerers usually don't have too much of a problem with this. There are specific astrological condition required. For example, the strongest ones, Third Circle Demons, can only be summoned during a five day window called Calibration once a year. First Circle Demons are numerous and interchangeable, while Second and Third Circle Demons are unique.
Demons aren't, unlike the D&D version, naturally depraved and evil. They are, however, the products of a nightmarish culture created, ruled by, and located inside of a number of beings that are almost as unnecessarily assholish as they are bugfuck nuts. They may be capable of moral choice like humans, but that doesn't automatically made them good people either. Unless you're a Sidereal with the charm that lets you essentially put them into the Witness Protection Program for services rendered, tread lightly.