2. Captain Cold
Other than Reverse-Flash, Captain Cold ranks as the Flashs most notorious enemy. As the man who mastered absolute zero, Cold is an opposite reflection of his hated enemy. While Flash uses speed to stop crime, Cold uses his freezing gun to commit crimes, and since frozen objects move slower at an atomic level, Cold is in essence using slowness as his trademark. When he was introduced in the late 1950s, Cold built his gun using a stolen cyclotron, although he had no idea that freezing would the effect. Donning a blue parka and an 80s visor, he fought the Flash using his new gun but was swiftly defeated. In the decades since hes fought the Scarlet Speedster many times and has gained notoriety as DCs second most famous cold villain after Mr. Freeze. As mentioned earlier, Cold banded together with several other Flash villains to form the Rogues. Working together, they perform heists and help each other if The Flash tries to stop them. However, unlike many DC villains, Cold has a strict moral code that he follows. The most important rule he implements on the team is not to kill unless its absolutely necessary. This a crucial characteristic that should be kept for the television series. Cold may be a thief, but dont vilify him to the point where hes killing civilians with his cold gun. Make sure pulling off a great heist is his most important goal. As for Colds M.O., make sure you keep him as just a guy with a cold gun. In the New 52, Cold used a machine that merged him and several of the Rogues with their weapons to give them the same type of powers. As a result, Cold is cryokinetic. While this may work for the comics, I dont think its a good fit for the show. Despite Barry gaining superpowers, Id imagine that getting powers is a lot harder to do in the TV universe. Give Cold a gun, perhaps powered by the energy from the particle accelerator like Mirror Masters weapons, but dont give him his own abilities.