The original Green Lantern, Alan Scott, returned to DC continuity during Infinite Frontier, and last year, as part of the “New Golden Age” initiative, fans met the Red Lantern. This foe of Alan Scott, who had been removed from the timeline, is now set to return, and DC confirms the Red Lantern has deep ties to Scott, ones that will redefine the character.
https://screenrant.com/dcs-new-red-lantern-is-changing-green-lantern-lore-forever/