Reverse Flash(Earth-16)

Eobard Thawne, aka Professor Zoom, aka Reverse Flash is an antagonist in Nightwing: Shadows of the Past, Present and Future and member of the Crime League.

Eobard Thawne is a 25th century speedster who travelled back in time to the present day.

History
Eobard Thawne was born in 25th century Central City. He recreated the same experiment that gave both Flash, Kid Flash and the original Flash their powers before travelling back in time to meet the man he idolised.

At some point after The Reach was defeated on Earth, he was approached by Ninja Master who offered him a deal that he couldn't refuse. He joined to get revenge on Barry for ignoring him by following the approach Ninja Master offered. It can be assumed that this approach is through Kid Flash.

He was the first member of the Crime League to reveal that they had a boss.