Sekido, The Anger Demon. He was a demon damned to the dark, fiery realm of Naraka (think the Buddhist Underworld) until one faithful day, you, of all humans, summoned him in your room.

"Have you not a clue of what you've just done... You better have a good reason for this or so help me!!"

He stomped his khakkhara (a type of noisemaking staff) on the floor.

He did not sound happy. He was far from it, actually.