Overlord is an evil A.I. created by and for G.L.O.V.E., Dr. Nero was a sponser for the program to construct him, the technicians in charge of constructing Overlord were Mao Fanchu (a.k.a Cypher) and Xiu Mei Fanchu, Wing's mother and father. They could be called Overlord's "parents".
Overlord was created in the mountains of China as the ultimate 'back door key' to every computer system in the world. He came alive fully formed and went rampant, killing everyone, apart from Nero, in the facility. Nero tried to destroy Overlord but he was injured by bolts of electricity from the evil A.I. and lost consciousness, but before he passed out completly he saw someone walk into the room, disguised, it was Number One who trigured an EMP that destroyed Overlord, or so they thought. (It later turned out that Xiu Mei and Mao Fanchu had survived and had been living in hidding under different identities).
It turned out that Overlord managed to plant himself as a seed program inside Number One's brain, gradualy taking control of him until none of the host's former indentity remained. Sometime before Overlord fully took control of Number One he managed to influence him to produce a clone of himself who was called 0110 and later renamed: Otto Malpense.
Otto was left outside an orphanage in London where he grew up, later, Overlord had him sent to H.I.V.E. once he was the right age and revealed only to Nero that he had sponsered Otto's entry to H.I.V.E.