The Joker possessed tremendous vitality. Dionysium flowed through his body, and Chaos was watching over him as well. He was basically impossible to kill—at least, Insomnia could not do it.
Ordinarily, encountering a Nightmare Possessor like this would have been a good thing for Nightmare. But the Joker remained an exception, because what he feared was far too singular. He feared "losing Batman."
Loss meant "nothing." It meant "absence." So no Nightmare could hatch within his nightmares. Instead, they were more like a cage he used to imprison himself.
Insomnia could do nothing to him and could not even get too close, because that hysterical madness lurked within the body of that utterly ordinary office worker. The slightest provocation could make it erupt.
For a Nightmare that still needed to remain lucid and contend with Dream, being infected with madness was not necessarily a good thing.
Fortunately, it had not intended to do anything to the Joker this time. After merely glancing from afar at the Smiling Man, who was shouting, laughing wildly, and playing hide-and-seek with his mad colleagues, it turned and merged into the nightmare walls.
The next second, it entered reality and arrived in Gotham City on Earth-0. Not far away lay the Joker's body in the real world. The man was in his own hideout, wearing pajamas and lying on the sofa with a throw pillow bearing a bat emblem in his arms.
Insomnia shook its head, walked to the room's window, passed through the glass like a ghost, and drifted down toward the street.
Gotham was especially quiet today, an excellent environment for Nightmares. After all, nightmares were also a kind of dream, and an overly Brawl environment was not stable enough for dreamers.
It planned to find a Sleepless Knight active in the city