The Ayakashi are ancient spirits with nightmarish forms that serve the Gedoshu and the antagonists of Samurai Sentai Shinkenger. This race consists of about 39 spirits.
They are creatures who live within the depths of the Sanzu River who gain power by terrorizing humans. They are capable of entering into the living realm by being summoned through a gap. However, Ayakashi require the water of the Sanzu River in order to survive, and thus they can only remain in the mortal world for a limited period of time until they begin to dry up and have to return to the river to regain their moisture.
Every Ayakashi has two lives, with the second life allowing them to grow giant once their first life is slain while they are regular-sized in battle.