King of the Silent Bliss of Nirvana
First appeared in Touhou 19: Unfinished Dream of All Living Ghost as the main antagonist, final boss for most routes, and playable character.
Based on the Sengoku Era monk Nichihaku Zanmu, Zanmu is a human monk who turned into an oni. As an oni, she became one of Hell's most influential voices, being the one to propose the separation of Former Hell and New Hell. She has red eyes, long, black hair with small yellow horns. She wears a green shirt and blue shorts with flip-flops.
In UDoALG, she masterminded the events of the game in order to prevent the Animal Realm yakuza from triggering a total surface war with the Hell oni. By biding their time, the incident where the relinquished ownership rights of the surface naturally resolved itself.