Doctor Manhattan and the World Forger's Game of Hide-and-Seek

What Brainiac called "destruction" was different from the "devouring" Barbatos had once used to brutally swallow an entire universe whole, leaving only an empty shell behind.

The former merely severed the energy that should have returned to the World Forge. Those destroyed universes were only destroyed on the "current" timeline. In the "past" of the Over-Time Stream, their timelines still existed.

Put simply, if a universe were a living person, Barbatos would be hacking that person apart, boiling the corpse into a pot of prion soup with everything censored, drinking it, and then smacking his lips twice before calling it a day.

But even if that "living person" died, the chemical energy contained in the corpse would still be absorbed by Barbatos. One day, after Barbatos was defeated, he would spit that energy back out, and it would rejoin the cycle of the entire Over-Time Stream.

Just as a raindrop falling into the sea would eventually turn back into water vapor and condense into a rain cloud in the sky, Barbatos had only absorbed the energy. He had not made it vanish from existence.

But the method Brainiac had proposed now was to erase the living person's existence completely. Past, present, and future—the entire universe would vanish from the Over-Time Stream as though it had never existed there at all.

That was precisely the goal the World Forger wanted to achieve: permanently weakening the Over-Time Stream this way, then appearing at the right moment to harvest all the energy Brainiac had gathered for destruction and use it to forge an Over-Time Stream of his own.

"If we want to pull this world's past, future, and present completely off the Over-Time Stream, the first step is to destroy this world's future. That's also the simplest step."

Brainiac told Black Death Emperor,