The final season of "The Flash" will introduce the live-action debut of the evil speedster, Red Death. There have several leaked behind-the-scenes photos showing the speedster villain in full costume, but it is unknown who is the actor behind the suit.

"Batwoman" TV series main actress Javicia Leslie will join the cast of the show, but there are hints that she might not be reprising her role as Ryan Wilder in the final season.

Who is Read Death

Red Death first appeared in the "Dark Nights: Metal" comic book arc. He is an evil version of Batman from the Dark Multiverse.

In his universe, he tries to capture Barry Allen/The Flash and steal his powers in order to use the Speed Force to travel back in time to save his Robins and fix everything in his past to prevent the deaths of his loved ones.

However, Barry tells Batman that changing the past will only make things worse in his present timeline. As a result, the Dark Knight started hunting him down using weapons from his past enemies, The Rogues.

Batman eventually catches Flash and ties him to a makeshift cosmic treadmill in order to siphon his powers. The machine explodes and both heroes are fused into one being. Calling himself Red Death, he began killing criminals in Gotham. But the use of his powers shattered his reality.

As his whole world starts to crumble, Red Death was then recruited by The Batman Who Laughs and joined other evil Batmen from the Dark Multiverse to conquer Prime Earth.

Twitter username Suffering Sappho posted leaked bts photos of Red Death in full costume and will likely the final opponent for Grant Gustin's Flash in the final season.

This could be Barry's biggest challenge yet as he dealt with other powerful speedsters such as Eobard Thawne, Zoom, Savitar and Godspeed.

Javicia Leslie joins the show

According to Entertainment Weekly, The CW Network announced that "Batwoman" star Javica Leslie will join the cast of "The Flash" in its final season.

However, EW adds that details of her role and number of appearances are being kept under wraps.

Leslie plays Ryan Wilder, the successor to Kate Kane as Batwoman after Ruby Rose left the show in its first season. Ryan has been making headlines as the new Dark Knight in Gotham City fighting criminals both old and new. Her recent adventures include his estranged psychotic haft-brother, Marquis Jet.

Several rumors and theories hint that Leslie could be Red Death since she is the only Bat-themed hero in the Arrowverse left.

Leslie previously made an appearance last season as Batwoman in the "Armageddon" crossover helping Barry defeat Reverse-Flash after changing the timeline once more.

The final season of "The Flash" will air in 2023 on the CW.