The Quest-class (支配能力 [クエスト･クラス], Shihai Nōryoku [Kuesuto-Kurasu], translated as Rule Ability) is a special breed of demon with the ability to create something from nothing; literally materializing objects seemingly out of thin air. These tangible, yet in most cases invisible objects are usually a derivation of some kind of weapon. This unusual power makes this class of demon's most formidable foes. The only confirmed member of this class of demons is Karasu, although Hokushin has demonstrated a similar ability to a small degree. It is implied that at least the demon has to be a B-class to master the technique, making it a subcategory of the B-class. It has been speculated that because of their powerful abilities, Quest-class demons typically hold governing-level positions in demon "society." It is unlikely that all demons with materialization abilities are Quest-Class, however (i.e. Bui and his axes, Rugby and his rugby balls).
- Karasu, a member of Team Toguro is the only-known member of the Quest-class demons; his power revolved around the ability to create different types of bombs.
- It is implied that demons of the Quest Class are fairly strong as Kurama stated he didn't stand a chance against a Quest-Class demon in his human form when fighting Karasu.
- ↑ Yu Yu Hakusho Episode 55.