Leading the candidates to die in the crossover are alternate universe speedsters Jay Garrick and Jesse Quick. The super-fast superheroes of Earths 3 and 2, respectively, the two heroes have ventured to the Arrowverse's Earth-1 on numerous occasions to help Team Flash. The older speedster effectively retired his superhero persona after facing his own advancing age in the fourth season of The Flash, while Jesse Quick has formed her own team of superheroes to defend Earth-2. While Jesse's death is unlikely, a potential demise for Jay would give the elder statesman the chance to emerge from his self-imposed retirement for one last race, if only to go out in a blaze of glory.
Another possibility is for Nora's own superhero alter ego, XS, to meet her untimely end in the upcoming crossover. The potential birth of the character towards the end of Season 5 would provide a poignant symmetry to her arc as well as give Nora the chance to redeem herself after disrupting the timeline in the first place. However, to introduce the character just to kill her off midseason, especially for a series looking to recalibrate its tone to the lighter, more optimistic outlook of the initial years, may be big step in the wrong direction. To suddenly kill Barry and Iris West-Allen's daughter before their eyes isn't exactly an upper of a storyline.
The most likely speedster to perish heroically in the crossover is Keiynan Lonsdale's Wally West, offering the actor the chance to return to the series and give Kid-Flash one final blaze of glory. After appearing as a series regular on Season 4 of Legends of Tomorrow, Lonsdale announced his amicable decision not to return as a series regular on either The Flash or Legends for the upcoming 2018-2019 television season, citing a desire to pursue new opportunities. With this in mind, Lonsdale noted that the possibility for his return was open, and later confirmed he is guest starring in Season 5 of The Flash after all. A noble sacrifice in the face of the coming Crisis to save the Multiverse and spare Barry Allen could be just the grand exit the character needs.
DCTV returns to The CW this fall with The Flash leading the charge on Tuesday, October 9 with its Season 5 premiere at 8 pm ET/PT, followed by Season 2 of Black Lightning at 9 pm. Supergirl will follow the next week on Sunday, October 14 at 8 pm, with Arrow the next day on Monday, October 15 at 8 pm. Finally, DC’s Legends of Tomorrow will return on Monday, October 22 at 9 PM. The highly-anticipated crossover will air over three nights, starting on Sunday, December 9 through Tuesday, December 11.