Haruka is a onieating tengu the strongest of all youkai. Kantarou having named him became his master and friend. Haruka has the ability to control lightning. Occasionally such as when he is attacking oni Haruka can transfigure into his true youkai form. His nails grow sharper and longer his fangs grow longer and his eyes constrict. Usually he appears as a tall darkhaired man with black wings that he can either hide or reveal. Haruka is troubled by his lack of memories inability to eat youkai and loss of power which starts to affect his sense of self. Haruka039s name under his previous master an onmyodo practitioner was Rin. As Rin he did not have a good relationship with his master and it is hinted that she took advantage of his subservient status for sexual purposes. Source: Wikipedia.