What we know:

He looks like a human.
He has a knowledge of technologies, to make such things as the spires and black digivice.
He doesn't come out at night.
He seems prideful, even after defete hes still seems pleased with himself
He wants complete controll of the Digital World, though we don't know why, seeing how he is not a Digimon.
*Warning*
Emperor Revealed
Spoiler information!