Kishin Douji Zenki

from wikipedia: enno ozuno, master of the enno temple used the demon guardian spirit zenki to defeat the demon goddess karuma. after defeating karuma, he later sealed zenki away in a pillar until needed again. centuries later, his descendant, a school girl named chiaki enno (役 小明, enno chiaki, or cherry night in some dubs) 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 that appeared on her wrist when servants of karuma broke the seal that imprisoned a seed of karuma. zenki appears because the seeds of karuma (which look like eyeballs) start appearing and turning people into monsters and zenki needed again to eradicate this menace.