Roger Hayden

"Research has focused on Roger Hayden, a.k.a. Psycho Pirate, who claims to remember the night’s events. He said upon his arrest, “Worlds lived, worlds died. Nothing will ever be the same.”"

- Iris West-Allen's article on Psycho Pirate

Roger Hayden, alias Psycho Pirate, is an individual connected to the night of the Flash's disappearance in 2024.

Biography
Roger Hayden was involved in the events of 2024, when the Flash battled the Reverse-Flash before disappearing from timeline. He was arrested afterwards (presumably for criminal activity of some sort), and claimed to have the ability to remember the events of that night in the way they were supposed to happen, while many others have claimed contradicting versions of the events (whether the Flash was assisted by Supergirl and the Atom, or a team of Green Arrow, Batwoman and the Elongated Man. Psycho Pirate claimed multiversal awareness, speaking that the crisis event resulted in whole world living and dying. The research of his account continued 25 years later.

Powers

 * Multiversal awareness: Roger Hayden was aware of the multiverse and grave consequences for it as a result of the crisis.
 * Temporal awareness: Roger Hayden claimed to be able to remember the events of the crisis despite conflicting accounts presumably caused by timeline alterations.

Behind the scenes

 * In the main DC Comics continuity Roger Hayden/Psycho-Pirate is a supervillain, who originally relied on the fabled Medusa Mask for his powers of empathic manipulation. During the Crisis of Infinite Earths, an event in which Barry Allen sacrificed his life to save the multiverse, Psycho-Pirate was granted part of Anti-Monitor's power, allowing him multiversal and temporal awareness. This became the character's most defining feature, allowing him to see various "forgotten" variations of timelines and universes in DC Comics's omniverse.
 * The Medusa Mask, associated with the character of Roger Hayden, was seen as one of the artifacts in Jasper Winters' millhouse.