Dr. Mitchell Yung (often simply "Dr. Yung" or "Yung") is a major antagonist in the Enigma Shadow series. Having appeared first in Pokémon XD^2: The Return of Shadow, he was originally voiced by Sean Schemmel, and by Paul Dobson in The Waves of Truth.
Little of Yung's past is known, but what is known explains somewhat his terribly evil nature.
Yung's parents were both scientists as well, and were killed when he was young. The two were researchers on the Mewtwo project headed by the enigmatic Dr. Fuji and funded by criminal enterprise Team Rocket. (Ironically, this project took place on New Island, where much later the Shadow Research Institute was built.) When their creation turned on them and destroyed their lab, the entire project's staff was killed.
The easily impressible young boy took a perverse interest in Mewtwo and the field of genetic manipulation following the death of his parents. He absorbed information of computers and science like a sponge, soon impressing even adult scientists with his vast range of knowledge. Even at this age, he was beginning to plot his dream, under the guise of bettering the lives of people and Pokémon.
Pokémon Institute and the Mirage System
By the time Yung reached his twentieth birthday, his staggering amount of knowledge---already more than most men would have in their lifetimes---made his application to the Pokémon Institute a lock. He was roomed with another young researcher who would soon end up on the opposing end of his plan, Jeffery Krane.
Studying under the famed Professor Samuel Oak, Yung began developing his dream: the Mirage System. Capable of producing living, breathing Pokémon out of raw data, and then being able to manipulate those projections into using attacks and abilities not normally associated with their species, Yung promoted his system as a brand new way for trainers to sharpen their skills against all sorts of opponents.
Or so he said.
The scars of his childhood still open, Yung truly desired to complete the Mirage System as a way to finish what his parents started: Mewtwo, the ultimate Pokémon. In order to do this, he would first have to gather data on all Pokémon, then combine the entire lot of it into a Mirage System-generated Mewtwo body. This hunger for data was his downfall, as Krane witnessed him torturing a Magikarp one night, draining its memories in an attempt to find a genetic marker of the long-past era when Magikarp was the strongest Pokémon on Earth. Krane reported the incident to Oak, and Yung was expelled from the Institute.
After being off the map for some time, Yung suddenly resurfaced in an apology letter to Oak and the Institute. He apologized for his actions and promised he had changed, and asked to be allowed to finish earning his doctorate by taking online classes. Oak approved the request.
Little did anyone know, hatred and evil were already hard at work twisting Yung's desires. His apology was truly a sham, only used to get on Oak's good side so revenge could be had later on.
Finally, Yung completed his Mirage System, and invited several young trainers as well as Oak to his giant, castlelike laboratory to help him test it. During the testing battles, a "malfunction" occured when the system was commandeered by a mysterious masked man, resulting in the kidnappings of Yung and Oak. The man sought data and stole every last bit of it from Oak's database, and also drained the memories of one of the trainer's Pikachu towards his ultimate creation---a Mirage Mewtwo.
The man was soon unmasked as being none other than Yung himself, having concocted an elaborate scheme for revenge against Oak, the Institute, and the world. He intended to take over the world using his unstoppable Mirage Mewtwo, but did not count on his system betraying him. A glitch in one of his tests produced a Mirage Mew with a soul that opposed him to the bitter end, holding back Mewtwo's attacks so the trainers could destroy it even though Mewtwo's end meant the death of Mew as well. The massive amounts of data being erased back into the system caused it to explode and collapse, but rather than give up his dreams, Yung pretended to commit suicide so he could escape to the underground world.
Now a garishly twisted caricature of evil, Yung vanished---many believed him to be dead---and began working on a new system more powerful and evil than the Mirage System. Hatred and lust for revenge fueled his desires---it seems that at this point, his true feelings were long lost.
At some point he joined the ranks of terror organization Enigma Shadow. His history within the group is unknown, but he rose quickly in the ranks to become the boss of the organization's work in the Orre Region. Upon the arrest of Queen Shadow Maria, Yung became the de facto head of all of Enigma Shadow.
At this time, he put his plan for ultimate revenge into motion. When the heroes attempting to stop Enigma Shadow arrived at his palace and discovered his identity, Yung unveiled his new invention: the Shadow System. Combining the Mirage System design with the Shadow Pokémon science, Yung intended to cover the entire world with Shadow System energy generators, in turn allowing him to convert all the world's Pokémon into Shadow Pokémon to do his bidding.
After two battles at seperate times, Yung and the Shadow System were defeated---even though he captured Rayquaza with it---and again, his dreams were dashed. He escaped to an unknown location once again.
Seven years later, with Maria out of jail and back leading Enigma Shadow, Yung was reduced to merely being a technician on their projects once more. He, along with Gordor---another scientist and former boss of the Go-Rock Squad---were working on a Capture Styler specially designed for evil uses, the Shadow Styler, when Gordor was murdered by an unknown entity. Yung completed the Shadow Styler himself and soon set about a new project: the Dark Styler, a Shadow Styler stronger than anything else ever seen before.
He is very dedicated to his work ensuring the loyalty of all the minions to Maria and completing the Dark Styler. However, Yung seems very bitter towards Maria, especially when he must perform tasks for her that he feels she should do herself. He longs for the day he can finally exact revenge on Rich and everyone else he feels has wronged him.