Thinking about this process, Shiller truly felt the difficulty of this copy. The requirements for players in this copy are really high. Just having strength isn't enough, neither is purely intelligence. You need to be proficient in both and possess endurance and willpower for long-term combat. Even if these are all present, you still need to have good luck.
Aside from basic strength. At the very least, you need to find a way to sneak into the Cathedral. While searching, critical information cannot be missed. If you're unaware that Batman's body has already been tainted by Joker's genes, even if you later find Batman's real brain and put it back, the one you save will only be the Joker.
Another crucial difficulty is figuring out which brain belongs to the Joker and which is Batman's. This is actually the hardest part because not everyone has Shiller's ability to hallucinate visions.
Ordinary people rarely think of brain swapping, and even if they do, who can guarantee that the brain inside Batman's body belongs to the Joker, and the one in the water tank is Batman's brain? Even if the Death Angel wasn't dead, he probably wouldn't tell the players. They can only rely on their own judgment.
Not many can come here in the first place, and even fewer can make the judgment. From the information provided by Batman's brain, it seems only Arkham Batman succeeded.
But even so, he was still forced to put Batman's brain into the polluted body. But that's quite normal because Batman doesn't kill. He possibly didn't fatally strike Death Angel, Tone, or Lady Siwa during the previous operations, resulting in having no suitable body to host Batman's brain, forcing him to use the previous broken corpse.
However, this also means that at that time Arkham Batman was desperately in need of another person's strength to help him. This proves that his condition was definitely not good then. Either he was injured or the situation had escalated beyond his capacity to solve it alone.
Shiller rummaged through the room and found a portable device, likely the preservation equipment Death Angel used to transport Batman's brain here, it's a box capable of holding solutions.
Shiller first poured out some solution from the water tank, then fished out Batman's brain, placing it into the box. Although he didn't know the principle behind this peculiar brain swap technology, Death Angel succeeded after all, and there's no reason he can't succeed.
Shiller picked up the box, not even glancing at Joker's brain in the tank, and hastily left Arkham Asylum's underground.
Just upon reaching the ground, Shiller was somewhat speechless. The patrol squad that had just passed in front of him was equipped with night vision goggles. They didn't have this stuff when he arrived.
This proves that the behind-the-scenes manipulator has discovered his night vision ability. To pursue fairness, he added night vision goggles to the airdropped supplies. It's clear he doesn't want Shiller to rest easy.
"This is bogus fairness," Shiller thought to himself. "The behind-the-scenes manipulator saw that I have the ability to see in the dark, so he equipped the sect members with night vision goggles, but he fails to realize that my night vision ability comes at a cost while everyone can wear the goggles. This is entirely unfair, unbelievably hypocritical."
"But this is precisely his weakness. These sect members were originally just ordinary people. When they couldn't see, they became extra alert, fearing something might spring out and catch them off guard in the darkness. Fear made them extraordinarily cautious. But once equipped with night vision goggles, losing the fear of grappling in the dark, they felt overconfident and became more lax. This makes them easier to deal with. Mad Laugh's grasp of human psychology remains superficial, as always."
"Enough of this," Shiller paused slightly when darting out of the alley. He said in his heart, "Can you both stop making noise?"
"This is merely a necessary reminder," he thought again. "Being able to see in the dark doesn't mean there isn't a blind spot, and the comfort from restored vision lulls them into dropping their guard. I can completely exploit this to reduce the difficulty on the way back to the city."
"Stop analyzing, let's just get it done," Shiller thought.
He deftly maneuvered through the alleys. Despite holding a box, his agility wasn't at all compromised. And those patrol members with night vision goggles indeed relaxed their vigilance, unlike before when they couldn't see and looked around left and right, turning heads constantly. Now they brazenly marched forward, with a somewhat crab-like swagger.
Moreover, there were more Rebel army members on the road, and their equipment had upgraded significantly. Many also got night vision goggles from the airdropped supplies. Both sides were evenly matched. Occasionally, the sounds of explosions and machine gun fire on the streets perfectly masked the noise from Shiller's movements, making the return journey rather stable.
After sneaking and hiding for over three hours, he finally returned near the Cathedral. Shiller once again infiltrated underground.
Sect members seemed forbidden from entering the laboratory room. This means Lady Siwa's corpse hadn't been discovered at all. Shiller searched the room again and found the lantern containing nano-equipment from before.
He carried the lantern near Lady Siwa's location. Some particles flew from Lady Siwa's corpse into the lantern.
When Shiller killed Lady Siwa, he realized her control over the nano-equipment was less than optimal. The healing speed was slow, and there was no method using nanobots to kill the enemy. Even compared to the strength depicted in the comics of Nanobatman, she was lacking. Thus, he surmised that controlling this stuff might also require some talent. Perhaps aside from Batman, nobody could perfectly wield the nano-equipment.
Taking the lantern with nano-equipment, Shiller returned to the Municipal Hall. Death Angel Paul's corpse remained as it was. Due to the brief duration of death, there seemed to be little change.
He turned the corpse over, placed the nano-equipment on its chest, grabbed the Death Angel's hand, held the lantern containing the nano-equipment, then smashed Paul's skull and inserted the brain encased in solution.
"This is utterly ridiculous," Shiller couldn't help but say. "This cosmos is absurd from beginning to end. Every cosmos on this side is absurd."
"Shut up," he continued. "Both your cosmos and the other side have their own absurdities."
He paused again, rubbed his temples with his hand, and lowered his voice, "Can we stop arguing with ourselves? I don't want Batman to think I'm a madman!"
"There's no 'we'. I'm just Shiller. And ordinary people sometimes argue with themselves, right? Sometimes they are distracted by thoughts unrelated to the current event. This proves I'm one step closer to being ordinary. Isn't that wonderful."
"I'm going to block the spiritual analysis in my mind concerning the relationship of this cosmos's death, Angel Batman, and the Joker. My brain doesn't need this soap opera-like rubbish!"
"Of course, I need it. If I don't clearly analyze their motives, how can I grab the tail of the behind-the-scenes manipulator from the clues?"
"Didn't I say? The behind-the-scenes manipulator wouldn't dare show up personally. What use is it to grab his tail?"
"That's not right. If he doesn't show up, I can force him to. It's not about relying on the manipulator's courage, but about leaving him no choice..."
Using nano-equipment, Batman, who reawakened inside Death Angel Paul's body, found himself saved by this guy, who stood in the darkness by the door, seemingly madly talking to himself.
"Are you okay?" Batman spoke with the voice of the Death Angel, finally pulling Shiller back from his world.
Shiller felt a headache. He indeed hadn't expected multiple personalities to surface consciousness, causing interference with thoughts.
They indeed wouldn't converse like patients with dissociative identity disorder, saying one thing, then another, as if different people were dialoguing. But they indeed resemble ordinary people more, who when thinking about something disperse in thought, pondering in one direction, then another.
Actually, this is normal because if someone's thoughts always revolve around a specific characteristic intensely, they'd become obsessive. More dispersed thoughts mean more comprehensive and diverse perspectives, which help enhance the activity of thoughts and the stability of the mind, allowing for a healthier mental state.
But the problem is, Shiller doesn't want health now. It must be admitted that some obsessives are indeed stronger. Because their thoughts are consistent, not disturbed by any external matters. Because of focus, there is strength.
Now Shiller's mind flips through analysis, flipping through ideas. Just after analyzing the mysterious relationships among the three protagonists, he's thinking about how to wrap a big yarn ball to strangle the manipulator. He can't focus on the current situation.
But considering the subsequent operations that involve using illusion vision, Shiller can only endure it for now. Yet he soon found that this interference was more serious than he imagined.
"Explain what's going on," Shiller said to the Death Angel—Batman.
"Most of your guesses are correct," Batman said, "just there's another point. Death Angel Paul never intended to make me like that. It was needed for the experiment. I completely disagreed with his brain swap plan because I believe no one should endure such pain, not even the Joker. But he went ahead stubbornly. We parted ways over this."
"I fear it's not so simple, is it?" Shiller chuckled, "If the Joker didn't agree voluntarily, even if the Death Angel could defeat and capture him, it couldn't have been so quick. Drag it out for years, and it's still doable. But if I'm not mistaken, the brain swap occurred as soon as the experiment plan started. Almost all the pain was endured by Joker."
"...He saved me," Batman's tone turned dry, "I must admit this. Even as a criminal and madman, he bore fifteen years of pain for me. For a long time, I couldn't figure out why he'd do this. But..."
"The criminals in Gotham love you more than you think. Whether it was the Death Angel who defeated you or the Joker who swapped brains with you. You originally thought they were utterly vicious, lacking a shred of normal human love and compassion. But after all this happened, you found it wasn't so. The most unacceptable yet unavoidable truth is that twisted love is still love. As a beneficiary, you can no longer stand on the moral high ground to accuse anyone of being twisted."
Batman opened his mouth just ready to speak, Shiller covered his forehead with one hand, stretched out the other, and said, "Sorry, I'm not trying to flirt with you. I'm just... a bit confused."
Then he turned in his consciousness and roared angrily, "Arrogant!! Get down!"