Zenjuuro Saotome

Zenjuuro Saotome is introduced as a "friend" of the principal. He graduated from Ishiyama High, the delinquent high school the main characters used to attend, and is now apparently a formidable teacher. He demonstrates formidable strength when he beat Oga, Izuma, and Toujo in a matter of seconds. Also, he appears to be both Toujo and Shizuka's mentor, and a spell master from the Demon World. Zenjuuro is the most powerful human described so far, and one of the most powerful characters in the series shown so far. He shows superhuman strength, speed and agility and is able to defeat uncontracted demons with relative ease, including Hilda, as well as being able to defeat Toujo, Oga, and Izuma with little effort. Even Behemoth has expressed that he would rather not fight him if he could avoid it due to his strength. It is implied that he has access to information from the demon world that…