That sound-- Apartment 3-E's door closing! That must be Mr. Xavier-- My mysterious next-door neighbor... The one I know nothing about... Or have even seen... Until now! 
Mister Xavier was the human guise of the alien saboteur Xviar, an agent of a mercenary organization identified only as "Homeworld."
History
"Homeworld" had been contracted by the Galactic Spaceways Company to destroy the Earth within a 30-year period, in order to clear a planned transportation route through the Solar System. To that end, Xviar was dispatched to Earth, coincidentally arriving on the same day that the rocket of the infant Kryptonian Kal-El crash-landed on the planet. Xviar murdered all human witnesses to his arrival and entered society with a superficially human appearance and a new name as "Mister Xavier." However, Xviar's disguise was imperfect, as "Homeworld" constructed it without accounting for the inevitability of human aging and its visible effects on the physical constitution. In order to circumvent the problem that this would cause his mission of infiltration, "Xavier" decided to live as a virtual cipher on Earth, eschewing any familiar or long-term relationships with the planetary natives and spending most of the next few decades in guarded seclusion. Xavier took up residence in Smallville, Kansas, at first, when it became known to him and his superiors that a Kryptonian refugee was active on Earth as Superboy. "Homeworld" conducted an advanced probabilistic study based on available data to determine that Superboy was likely to move to the city of Metropolis as an adult Superman; therefore, Xavier was instructed to go there many years ahead of time to prepare further observation of Kal-El's developing career. "Homeworld" remained confident that Xavier could manipulate the vast destructive potential of Kryptonians under yellow-sun environments to accomplish their mission and ordered him to rent an apartment in the building at 344 Clinton Street, having projected that Kal-El's likely course of action would be to seek residence in the very same building in his maturity.[1][2]
Nearly 3 decades later, Kal-El had become the Earth's best-established hero as Superman and lived in an apartment at 344 Clinton Street as WGBS anchorman Clark Kent, fulfilling all Xavier's predictions to the letter. Clark occasionally wondered about his reclusive fellow tenant and on one lonely night even trailed a man who he thought was Xavier from the adjacent apartment for several city blocks, in order to deduce Xavier's occupation from his route and personal attributes. Eventually, Clark was caught by the man he was following, who not only turned out to be someone other than Xavier but scuttled Clark's deduction that he was a mailman by revealing the truth that he was really a night-watchman with past experience as a private detective.[3]
A few years later, Xavier received orders from "Homeworld" to execute his mission in earnest. Such involved breaking into Clark Kent's apartment during his absence and treating his entire wardrobe with a chemical agent that would strongly absorb the frequencies of EM radiation from which Superman draws power. The deliberate intent of this was to mislead Superman into believing that the reason for why he could access none of his powers as Clark Kent any longer was psychological. As a result, Kal-El was spurred to subject himself to a psychological experiment in preparation for abandoning one of his two identities, whereby he would spend a full, uninterrupted week as Clark Kent, then another as Superman. During the latter, Clark's apartment was left completely abandoned, this being Xavier's objective, as it gave him time to scour Clark's apartment for his private exhibit of artifacts from past adventures and locate a set of energy-crystals. Xavier then hid the crystals elsewhere in Clark's apartment and psychically congregated 9 of Superman's greatest enemies-- Lex Luthor, Brainiac, Parasite, Mister Mxyzptlk, Terra-Man, Toyman, Amalak, Prankster, and Kryptonite Man-- in the apartment. This drew Superman into quickly returning to the apartment, whereupon Xavier scattered the gathered villains to various locales around the world and allowed Superman to unknowingly expose himself to the invisible radiations of the energy-crystals. Then, Xavier telepathically beamed the locations of the villains to Superman's mind in the hopes of causing confrontation; upon Superman's defeat of his final antagonist, the Kryptonite Man, Superman's body would have exerted enough work that the charge imbued it by the crystals would have caused it to detonate in an exposion sufficient to shatter the Earth. However, Superman deduced Xavier's scheme when he realized that he still had his super-powers while dressed as Clark Kent using a suit from the WGBS wardrobe room, detected the chemical contaminant in his apartment wardrobe with his super-vision, and traced a separate trail of ionized particles, responsible for beaming the telepathic images into his brain, to Xavier's apartment. After Superman defeated Brainiac and Amalak in the way of running Xavier's gauntlet, Superman deposited them in a prison complex at the edge of the solar system to detain them; to escape the expected destruction of the Earth, Xavier teleported himself to take Amalak's place in the complex, leaving Superman to face the K-Man. Fortunately, Superman had the foresight to wear a contaminated Clark Kent suit underneath his Superman costume, thereby negating his powers and allowing him to take K-Man out with a single non-super-powered punch to the jaw. Because no exertion of super-powers was involved in the feat, Superman's body did not detonate and the threat to Earth passed. Superman then confronted Xavier personally in the outer-space detention complex, informing him that while he may have thought "Homeworld" would break him out if successful that they would not go through the effort of liberating a failure.[1][4][5][2] Xavier's apartment was later rented by Jackson Porter, an elderly widower.[6]
Powers and Abilities
Powers
Abilities
Paraphernalia
Equipment
- Various alien devices
Notes
- This version of Mister Xavier, including all history and corresponding appearances, was erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths event and later restored following the rebirth of the infinite Multiverse during the Dark Crisis of 2022-2023. Even though other versions of the character may have appeared, this information does not apply to those versions.
Related
- 4 Appearances of Xviar (Earth-One)
- 1 Images featuring Xviar (Earth-One)
- Quotations by or about Xviar (Earth-One)
- Character Gallery: Xviar (Earth-One)
Footnotes
  This character has been primarily an enemy of Superman in any of his various incarnations, or members of the Superman Family. This template will categorize articles that include it into the "Superman Villains category." |