Kryptonian scientist Doctor Xa-Du was convicted of conducting forbidden experiments in suspended animation which resulted in the deaths of those upon whom he was experimenting. He was sent to the Phantom Zone for his crimes, as was his wife Erndine Ze-Da, at a later date.
The pair managed to escape from the Phantom Zone but Superboy tricked them and exiled them to planet Exon which had a red sun. This meant of course that the Kryptonian villains had no super powers. Years later the pair returned, with a new power that worked when they gripped each other's hands. Superman imprisoned them on separate worlds in different galaxies.
The New 52
Due to their contradictory experiences with suspended animation Xa-Du was condemned by the K-Council to be dematerialized and exiled for eternity to the Phantom Zone,where he would be unable to feel pain and cause pain to any other person again.
Taking advantage of the long years in exile he studied Phantom Zone's secrets to develop a Ecto-Technology that would allow to walk amongst the living world,thus creating the Ecto-Suit which is powered by pure consciousness.
Major Story Arcs
The Ghost in the Fortress of Solitude
Hearing a noise Superman is attracted to the room where placed Kandor and a Phantom Zone projector,but was caught off guard by Xa-Du that used the projector to banish him to the Phantom Zone,fulfilling his revenge against House of El and giving him time to plan his attack on Earth.
IInside the Phantom Zone he struggles to survive the attacks of other prisoners, until be helped by Phantom Stranger who explained that Xa-Du's Ecto-suit is powered by willpower and that only through willpower could take control of the suit and turn back the projector to escape. So using his willpower Superman was able to take control over suit,which makes Xa-du to pulled back into the Zone.
Moments later received an interesting offer from the Little Man.
At the end of days
Shortly after it is revealed that he accepted the offer of the Little Man joining his Anti-Superman Army.
Alongside Anti-Superman Army invades the first Fortress of Solitude (a Brainiac Ship) to steal the kryptonite engine from Kal-EL's Escape Pod so the Little Man could create another isotopes from this material.
Later is seen fighting Superman in Metropolis.
While following Krypto in Doomsday's trail to the Phantom Zone ,Batman and Wonder Woman found Dr. Xa-Du using a device using a device which drains energy from dimensional rifts left by Doomsday when it broke the Phantom Zone.
Shortly after is captured by Wonder Woman and locked away in a special cage to restrain their powers, so Batman, Shay Veritas and Harrow created a plan to remove all kryptonite's particles off the planet giving Superman control over his body again. Harrow pinned Xa-Du between dimensons,while Luthor and Shay Veritas tap into his ecto-technology to turn kryptonite intangible and thus open several portals to other dimensions.
Getting rid of Harrow,he teleports away.
A series of mysterious attacks to people directly or indirectly related to Superman cause panic to everyone,clueless of who can be the murderer Clarks asks Batman for help. analyzing the recent attacks Batman says he is facing an obsessive, insane and remorseless assasin,in other words Superman got to himself a Joker.
Powers & Abilities
Due to being Kryptonian Xa-Du possess all abilities present in a Kryptonian under a Yellow Sun. However, due to still being a prisoner in the Phantom Zone and ,so if loses contact with the suit he will pulled back into the Phantom Zone.
- Superhuman Strength: He showed enough strength to go toe to toe with Superman and even break kryptonian's sunstones.
- Superhuman Durability
- Superhuman Speed
- Superhuman Stamina
- Superhuman Senses
- Freeze Breath
- Heat Vision
- Teleportation: Unlike other Kryptonians he has the ability to teleport, but it is still unknown whether it is a power of himself or something developed during exile in the Phantom Zone.
Ecto-Suit dependece: In order to able to walk among the living he needs to be in direct contact with his suit,but if loses contact with he will be pulled back into the Phantom Zone.
Willpower: His armor can be disabled or controlled by others with willpower, greater than his
Blue Kryptonite: He is apparently immune to green Kryptonite, but the Blue Kryptonite is extremely lethal because it can kill a spirit.