"But this would create problems too," Adventure Batman said with a frown. "While we concentrate our strength in one place, the other universes will inevitably be slaughtered by him. Can we accept those losses?"
The other Batmen fell silent. Clearly, none of them wanted to accept that, especially when Robin had already been harmed in quite a few of their universes. Batman could never accept Robin's death.
If they fought the mastermind this way and abandoned their own universes, it could very well lead to disastrous consequences. It was something Batman had no choice but to worry about.
Then it might turn into this: they went to the Main Universe, but their minds remained fixed on their own universes. The moment they received bad news, they would rush back. In the end, neither the Main Universe nor their own universes would be properly protected.
"There is another way," Main Universe Batman said. "We concentrate our strength and fight it over a universe it absolutely cannot abandon. If we concentrate our strength, it will have to do the same. It probably won't be able to attend to the other universes."
The Batmen began discussing it in low voices again. Of course, they knew which universe Main Universe Batman meant. They had long realized that the Main Universe was different. What troubled them was this: would the mastermind realize it too?
If the mastermind understood the Main Universe's importance, it would never abandon that territory. To keep the united Batmen from driving it out, it would certainly exhaust every means, use every bit of computing power, mobilize every thread, and preserve its arrangements in this universe at all costs.
Because once the Main Universe became completely safe, any Multiverse-level disaster would be more than halfway resolved. The invader would not want to