The Flash's Ultimate Villain Only Appears Once in DC Continuity
Reverse-Flash has always been one of The Flash's most disturbing foes, but the zombified transformation may be his scariest and most powerful form.
The greatest villain the Flash has ever faced has appeared only once in DC's vast history. Barry Allen's futuristic nemesis gets a terrifying upgrade that makes him one of the deadliest speedsters around.
Even though The Flash is the fastest man alive, there are many villains who keep challenging him. But of all the Rogues or Gorilla Grodds trying to take down Speedster, none pose as much of a threat to him as Reverse-Flash. Eobard Thawne from the 25th century hated Barry Allen so much he dropped everything to become Reverse-Flash and make Scarlet Speed's life a hell on earth. His hatred for Barry is so strong that Thawne learns to manipulate everything in the timeline just to ruin Flash's life. Thawne's coup de grace is of course killing Barry's mother and framing his father, leaving Allen an orphan.
Reverse-Flash's Black Lantern Form Is a Nightmare
However, a brief encounter with the evil Power Ring takes Reverse-Flash's play to a new level of villainy. In Geoff Johns and Scott Kolins' Darkest Night: The Flash #1, the DC Universe is attacked by Nekron, Lord of the Dead and his Black Lantern Legion. To aid him in his mission to destroy all life, he sends rings across the universe to resurrect heroes and villains and add them to his ranks. One such villain is Eobard Thawne, who resurrects and seeks out The Flash in revenge for accidentally breaking Reverse-Flash's neck and killing him. Knowing that word of what happened to Thawne is spreading across the planet, Barry chooses to run instead of running afoul of his zombie archenemy.
The Undying Lanterns are actually simulations created by their power rings, but they have all the same powers that the Black Lanterns had in life. Not only that, but they also possess abilities that the power ring bestows upon Green Lantern, such as flight and construct generation. So while this version of Reverse-Flash isn't technically Thawne, he's every bit as powerful as the villain and able to use his speed. In fact, with the added bonus of a Power Ring, he might be the most powerful version of Barry's nemesis.
Reverse-Flash with a Power Ring is A God-Level Danger
No matter how much Barry Allen knows about the Speed Force, he will always be confused repeatedly by someone who also knows about it it intimately. Eobard Thawne's mastery of time travel makes him one of the most dangerous men in the entire DC universe. But coupled with the unlimited power of the Black Lantern Power Ring, he's suddenly a god-level threat. A monster that can go to any point in time and kill almost anyone with immortality? Luckily for Barry, Reverse Flash's membership with the Black Lantern Corps was temporary, as he could have been Flash's worst nightmare.