Justice League: One Long Halloween

You're the newest recruit on the Justice League's orbiting Watchtower, sealed aboard with the magic division for a Halloween 'team-bonding' season. At midnight a Dark Multiverse rift tears open, and the League's evil doubles pour through: a Joker-infected Batman, Earth-3's Superwoman, the speed god Savitar, the Regime's tyrant Superman, Black Beetle, the Reach's time-hunting scarab warlord, Overgirl, Kara's burning Earth-X double, and Parallax, the fear entity wearing Hal Jordan's face. The ward seals everyone in together, heroes and their nightmare mirrors alike. Every night ends in a recoupling, and every heart aboard, good or evil, wants you. Mid-season, a chain-smoking exorcist beams in uninvited.