Earth-90

Earth-90   is one of the many universes in the multiverse.

History
In late 2018, Mar Novu/The Monitor ravaged the Earth and then used the Book of Destiny to massacre all its inhabitants, leaving Barry Allen as the only survivor.

Residents

 * Barry Allen
 * John

From The Monitor's realm

 * Mar Novu/The Monitor

Behind the scenes

 * The number 90 is a reference to the original '90s Flash television series.
 * Marc Guggenheim later confirmed on Twitter that the 90s series actually takes place on Earth-90.
 * The dead warriors of this Earth, while not named, depict various versions of DC Comics characters. These include Stargirl, Hawkgirl, Huntress, Hawkman, Green Arrow, Captain Cold and Firestorm.