Sanan is one of five ayakashi selected by Kokuboro as part of an advance guard to invade Karasumori. They are each given human skin so that they can enter undetected during daylight. Kaguro, as the highest ranked member of the the guard, allows Sanan to take command, as he is smarter than the other three by far. In his ayakashi form, Sanan is able to fly and use his sharp wings with lethal accuracy. He is also strong enough to lift and carry an ayakashi heavier than himself for some distance. However, in battle he generally stays above the action, observing and ordering his allies, and only getting involved when he has a role that the strategy directly depends upon.

(Source: Kekkaishi Wikia)