Forgotten Emperor

Ones upon the time, there is an Emperor, The first Emperor in all primordial times, He rule all intelligent life forms, only those unintelligent creation don't know his name... That is what it suppose to be, but one day many creature betray him, and as his defeat, he take his Empire with him and vanish in time and space, in every Era he appear but without his memory, in every Era he appear he was always stand at the top and vanish ones more, but on a certain reincarnation, he appear on a young man's body with all his memory intact, but not like any other of his reincarnations this time his not a novel or a powerful ruler, but a son of a rundown bar in the red light district.