Amon  

Angel of Time, God of Deceit, God of Mischief, God of Trickery, Lil, Lil’ Raven, Mr. Er, Mr. Error, The Blasphemer, 阿蒙

The character you're referring to has a crystal monocle in his right eye, curly hair, wears a black cloak and pointed hat. He is a high-sequence Beyonder and one of the main antagonists in Lord of the Mysteries. This individual is known for having a slightly unhinged personality, earning him the titles of Angel of Time and God of Mischief.