Doctor Double X

Doctor Double X (originally called Doctor X and Double X) is a fictional character in the DC Comics universe. The character is a supervillain who has fought Batman and Robin several times in Gotham City.
Publication history.
Doctor Double X made his first appearance in the pages of "Detective Comics" #261 (November 1958), in a story titled "The Amazing Dr. Double X" by Bob Kane, writer Dave Wood and artist Sheldon Moldoff.
Fictional character biography.
Dr. Simon Ecks is a scientist who discovered that human auras could be enhanced to function outside of the body. When Ecks created an energy-duplicate of himself, the introverted scientist's unstable mind became dominated by the doppelgänger he named Double X. He fought with Batman and Robin. The resulting battle causes Simon Ecks to lose his memory of the experience. He is remanded to Arkham Asylum.
Some years later, Simon Ecks regained his memory and developed another duplicator device that enabled him to escape from Arkham Asylum. Doctor Double X matched wits once again with Batman. This time, Batman was able to defeat him by building his own machine that generated an energy duplicate of himself.
Doctor Double X later escaped from Arkham Asylum and faced off against Batman and Superman. This time, it took both Batman and Superman to overcome him.
Doctor Double X once traded opponents with Flash villain Rainbow Raider after meeting a motivational therapist named Professor Andrea Wye. Both of them are defeated by Batman and Flash.
Doctor Double X was later seen as a guest at the San Francisco sci-fi convention. He was sitting next to Beast Boy who learned that Doctor Double X was washed up and forgotten.
In "The New 52", a reboot of the DC Comics universe, Batwing encounters Dr. Simon Ecks in the tunnels beneath Arkham Asylum. While he informs him that most of the Arkham Asylum staff was either taken or killed, he warns Batwing to stay back as there is something inside that wants to kill. As a spirit rises from Simon Eck's body and starts to reach towards Batwing, Jim Corrigan shows up and knocks out Simon Ecks as he states that the spirit is a Tulpa. When Batman dispels a ghost in a cemetery, it causes the supposed death of a man wearing an ID badge that has Simon Ecks's name on it. Batman then has Julia Pennyworth contact Batwing to look up any info on Simon Ecks.
Powers and abilities.
Doctor Double X's energy-duplicate shares the consciousness of Simon Ecks, but can also act alone. The duplicate's powers of flight, energy blasts, and super strength have at times required Batman to seek help in defeating the villain. Double X requires regular infusions of electrical energy to sustain itself or it will lie dormant in Ecks' body.
In other media.
Miscellaneous.
Doctor Double X appears in "Justice League Adventures" #29.