Kišin dódži Zenki

Enno Ozune, Master of the Enno temple sealed the demon Zenki into his power to defeat the demon king Kuruma. After defeating Kuruma, he later sealed Zenki away in a pillar until needed again. Centuries later, his descendant, a school girl named Chiaki Enno is able to free Zenki, although the demon currently has the form of a brattish demon child. To transform this extremely defiant demon into the form that made him useful by her ancestor, she uses a bracelet given to her by her grandmother. Zenki appears because the seeds of Kuruma (which look like eyeballs) start appearing and turning certain people into monsters and he is needed again to eradicate this menace. (Crunchyroll)