Bio: Melanicus was a demon whom Rassilon once banished for a thousand years. Described by Rassilon as a "master of time and space . . . a grand wizard of chaos", Melanicus once stole the Time Lords' "event synthesizer" and attempted to bring mass disorder to the natural flow of time. He was defeated, in the end, by the Fifth Doctor, Shayde, Rassilon, and Sir Justin — the last of which paid the ultimate price in bringing about the demon's downfall.
Though a native of the solar system of Althrace in our dimension, his banishment by Rassilon sent him into another dimension. He was only brought back to our reality by a magic ceremony performed by Catavolcus.
Notes: As Catavolcus was the principal enemy of the last Fourth Doctor comic story, it cam be said that "The Neutron Knights" forms a kind of prelude for "The Tides of Time", even though Melanicus never met the Fourth Doctor.