Zest is a powerful demon, originally created to serve Zolgear. After Zolgear's defeat, she served Sheila before forming a master-servant contract with Basara. A tall, slender woman with white hair and gold-green eyes, she possesses a rabbit tail and horns (not visible in human form). Zest is a highly skilled combatant, adept at close-quarters combat with sharp claws and capable of flight. She is also a master of magic, particularly earth magic, allowing her to control terrain, create golems, and manipulate earth elements. Her abilities increased significantly after forming a contract with Basara. She is also proficient in housework and domestic skills.