Leo Snart

Leonard "Leo" Snart is a fictional freedom fighter and superhero and a minor recurring character featured in the DC Television Universe. He played a major role in the "Crisis on Earth-X" storyline that began with an episode of Flash and concluded on "Crisis on Earth-X". The character made two more guest appearances on Legends of Tomorrow before departing from the series.

Biography
Leo Snart is a version of Leonard Snart from a parallel dimension dubbed Earth-X. He was the homosexual over of Ray Terrell, and was a member of a group of Freedom Fighters battling against the Nazi regime of Oliver Queen.

After assisting many superheroes from Earth-One in overthrowing the Nazis, Snart decided to take a little time to explore the timestream with the Legends. During his brief stay with the Legends, he tried to hold an intervention for Mick Rory and encouraged Sara Lance to pursue a relationship with Time Bureau administrator Ava Sharpe. He also met the British occultist John Constantine.

Following a time-travel excursion to a mental asylum in the 1960s, Snart decided it was time to return to his own dimension to be with Ray.