Time Commander

Time Commander is the name of two supervillains who used technology to manipulate time

John Starr
John Starr was a scientist working with the famous Dr. Elijah Carruthers on an artificial humanoid project. They successfully created the humanoid Cosmo, however he proved to dangerous and they had to destroy him and abandon the project. Now without employment, John Starr turned to crime and was incarcerated quickly. While in jail, Starr perfected an hourglass that gave him the ability to manipulate time. He used this technology to become the Time Commander. He escaped prison and went back in time to alter the evidence that got him convicted, but he was stopped by Batman and Green Lantern. He later escaped prison and recreated Cosmo as part of a plan to get revenge on Batman and Green Lantern. Cosmo went out of control however and nearly killed Time Commander, who cowardly fled the battle. Batman managed to find Dr. Carruthers who helped him and Green Lantern destroy Cosmo. John Starr moves to Paris, France where he begins selling his time control powers to make women younger looking and bring people back to life. He then gets the idea to return the world to the paradise Garden of Eden. Seeing the clear long term harmful affects of what he was doing, Animal Man, Metamorpho, Elongated Man, and Rocket Red worked together to stop Time Commander. Calendar Man breaks Time Commander out of prison along with Clock King and Chronos to become the supervillain team "The Time Foes". They come to battle the Teen Titans and are ultimately defeated. The Time Foes are later trapped in a time loop during the "Zero Hour" crisis, where they are apparently killed.

Sterling Fry
A former student of the original Time Commander John Starr, Fry took up the identity of his teacher. As the second Time Commander he kidnaps Liberty Belle in order to blackmail Hourman for his magical hourglass. After releasing the particles inside the hourglass fry disappears. He returns as a hero helping the Justice League defeat the villain Epoch. it is later revealed he only did this to steal John Starr's hourglass from the Justice League trophy room.