Season 8 of The Flash has launched, with a five-episode story arc -- they're calling it a "graphic novel" -- titled "Armageddon." It is a loose adaptation of the "Armageddon" crossover that ran (no pun intended) through DC's 1991 Annuals.
For TV, The Flash is facing Despero, come from the future to destroy The Flash before he destroys the future. So far so good.
As the lords of the Arrowverse shows have decided it's too risky to do the annual crossover (because, y'know, COVID), they are making up for it by having characters guest-star during this storyline. I appreciate their diligence. Part 1 had Ray Palmer show up in Central City to accept an award at a tech fair. Ray was kind of wistful about not being with the Legends of Tomorrow, and it seemed like Brandon Routh was, too. Part 2 had Alex Danvers providing intel about Despero (and a bit of exposition saying "Supergirl and J'Onn are off-world"). And the end of Part 2 sets up an appearance by Black Lightning in Part 3.