This demon is the leader of Labyrinth who wishes to rule all worlds, thinking of all his subjects to be only mindless pawns. He grants the members of Labyrinth their items.
In episode 49, it is revealed that the Moebius we have seen through out the series is just a robot. The real Moebius is a supercomupter that hypnotised its creators, i.e. the people of Labyrinth.(Source Wikipedia)