Charles Xavier (Legion Personality) (Earth-616)

This new personality, called the "Fiend", emerged due to the mental shock of Professor X's death. He has the form of a yellow little goblin-like creature with unknown power and later takes the form of Charles Xavier. He controls the Precognitive power of of David. Once he emerged, Fiend, killed Ksenia Nadejda Panov and devoured her so he could steal her power and have less competition.^[1] Then spend most of the time stalking David in his mind, but didn't make any move against him. He has the habit of hissing while watching David.^[2] When Blindfold telepathically entered David mind and restrained David and the other sub-personas around him, "Fiend", who was unaffected, angrily told her to get out while slashing her throat which caused her a psychic-trauma.^[3] Later when David was chasing Luca, who killed and possessed Sojobo, and was about to kill both him and Karasu, "Fiend" taunted and told him that his father would be ashamed of him if he saw him like this which caused David to lose his self-belief and allowed "Fiend" to take control and spank Karasu and tell Luca that he will be useful one day before David retakes control. Later he tell David that the grand evil that Luca foresaw, the one that will wipe out mutantkind was non other than David himself and Blindfold was destined to kill him to stop it and call David a disappointment.^[4]

David asked him how he had come to know all of this and "Fiend" answered that he knows everything, he then reveals himself to be in the form of Charles Xavier himself and call David my son. Later, "Xavier" helped David when he was attacked by an unknown entity and fought the entity in a way David wasn't able to and promised that all will be revealed.^[5] David reveals to Ruth on their date that it is not just him who afraid of this persona, but all of the other personalities are terrified of him. The reason of that is revealed when David went to make a deal with him and told him that he know that he was killing and swallowing the other personalities and their powers.^[6] "Xavier" didn't deny it and told David that he know why he came to him and it was to know if Luca's prediction of him wiping out mutantkind is true. "Xavier" confirmed it to be true and knew that David wanted to know for himself and that was why he came to him. "Xavier" told David that he will allow him to use his power in exchange for one minute of control of David body in a time of his own choosing. David accepted and used his power. After that, "Xavier" paid farewell to David.

Precognition: He has the ability to accurately predict future events and all its tangent possibilities.^[6]

Postmortem Power Absorption: Over the time he was trapped within Legion's psyche, Fiend/Xavier took to strengthening himself by killing other personas within the mental complex gaining their abilities in response.^[6]

• Ionic Scalpels
• Super positional Firebombs
• Tesla Songs
• Neutronic Time Crystals

Psychic Possession: Being a mental entity, Xavier has no corporeal being which is bogged down by the rules of physicality. He can reach out and possess other minds and bodies at will, as he intended to do with the Red Skull as well as doing so with the disembodied Luca Aldine.^[7]

Although never referred to as such in the comic, writer Simon Spurrier refers to this personality as "Professor Y" a play on the real Charles Xavier's codename of Professor X.