Season 9 cemented Barry Allen not as the fastest man alive, but as the best man alive.
The Red Death was revealed to be a variant of Ryan Wilder (Javicia Leslie), the Batwoman. This choice was brilliant for two reasons. First, it provided a heartbreaking foil to our heroes—a hero broken by grief who turned to darkness. Second, it allowed the Arrowverse to continue its interconnected legacy even as the universe was collapsing. Javicia Leslie’s performance was menacing yet tragic, providing a villain who wasn't evil for the sake of evil, but rather a warped reflection of what Barry could become if he lost his moral compass. The Flash - Season 9