Gotham's Gone (Pages 6-10)
We don't have much to say about the fire-breathing Joker-snakes on Page 6, except that they look pretty intimidating. We suppose there's a precedent in Steve Englehart, Marshall Rogers and Terry Austin's classic two-parter from February-April 1978's Detective Comics issues #475-76. Not only did the Joker apply his infamous venom to some helpless fish, but an innocent cat got ahold of the stuff as well. Page 7 finally showcases The Devastator, whose bones turn hard and grotesque like Doctor Death's in Snyder and Capullo's "Zero Year" storyline. Page 8 features the Batman Who Laughs and his Robins (or Crows, perhaps). He took over Gotham City in Teen Titans #12 and divided it among Mr. Freeze, Bane, Riddler, Poison Ivy and Mad Hatter. Specifically, he busted Mr. Freeze out of Arkham Asylum in Nightwing #29.
We agree that the four identical Evil Robins are probably Dark Multiverse counterparts of Jason Todd, who say only "crow" because it's part of the word "crowbar" –- as in the crowbar with which the Joker beat Jason to death.
On Page 9 Superman pleads that there must be "some good" in the Batman Who Laughs, but that theory gets shot down pretty quickly. The Crime Syndicate of Grant Morrison and Frank Quitely's 2000 graphic novel JLA: Earth 2 came from a parallel world which was as evil as DC-Earth was good, so not even the Justice League's intervention could turn them around. It seems that the Dark Multiverse folks, composed of every negative impulse from the "good" Multiverse, are about ten thousand times worse.
After brief cameos in previous issues, Doctor Fate makes his first proper Metal entrance on Page 10, creating a portal for the Flash to save Superman. Previously, Doctor Fate had rescued Flash from the Red Death and Green Lantern from the Dawnbreaker in the aforementioned specials; and had also rescued Nightwing, Robin, Green Arrow and Mister Terrific in Green Arrow #32.