Carthus' past is shrouded in mystery. He was a blue skinned being with several large red spiked horns upon his head and strange yellow glowing eyes. His existence became known when he escorted a group of young
Inhumans, which included
Dewoz, Dini, Kalikya,
Nahrees, Neifi, and
Tonaja, into the Terrigen Mists for the first time. This event was overseen by the Royal Family and the Inhumans leader,
Black Bolt. Dewoz step from the Terrigen Mists in the form of an
Primitive. Due to the fact that the Alpha Primitives were a slave race that was considered to be a lesser species that lived below the Moon city of Attilan. Carthus led Dewoz to the Alpha Primitives city to live and work with them. The Alpha Primitives were infuriated, although they took Dewoz in as one of their own. Carthus manipulated both Black Bolt and
Medusa to believe that Dewoz desired to work amongst the Alpha Primitives. Black Bolt and Medusa both believed the logical lie that their spiritual advisor had weaved. Later Tonaja and Nahrees approached Carthus, inquiring about Dewoz's status and whereabouts, they were also lied to. Carthus was present when Timberius approached the Genetic Council, requesting war with the humans after his brothers death.