Originally Posted by
Doctor Know
What Thezmage said. Faceless undead with black lantern uniforms and power rings vs the heroes of DC's animated Earth would be the way to go. Not a straight, one to one adaptation of the comic, but keep the spirit of the event.
Plus, the New 52 animated verse had a pretty stacked body count of known villains (Ra's, Brother Blood, Terra, Slade, Riddler, Silver Banshee, Doomsday, Reverse Flash), anti-heroes (Suicide Squad's dead members), heroes (Atlanna) and civilians to resurrect and wreak havoc.
With two 90 minute movies; you can spend part 1 with Hal and Carol recruiting the other Lanterns across the universe. Sinestro in Oa's prison (from First Flight), Atroticus, Saint Walker, Indigo, Larfleeze. A quest the Ganthet sends Hal on, to fulfill a prophecy of light up the dark.
While on Earth, the main League are dispatched across the world to defend cities, the Batfam defends Gotham, the Suicide Squad defends where ever Waller is, the Titans New York City, and the Dark League (Constantine, Fate, Zatanna and Etrigan have their own battle to fight. Remember Black Lantern Swamp Thing? I'd keep John Stewart on Earth and have Guy and Kyle defend Oa. Like in the comics.
Part 2 would have the 7 multi-colored Lanterns arrive on Earth for their battle with Black Hand and Nekron. With most of Earth's defenders being turned by the Black Lanterns themselves. Do the Lantern deputy thing from the comics and have Barry be Blue, Mera be Red, WW be Pink, Palmer be Indigo, Luthor be Orange and Batman be Yellow. Along with John Stewart and Hal Jordan, the 14 Lanterns defeat Nekron, Black Hand and restore life to the universe.