When Venom first parasitized Batman's body, it was completely overwhelmed by Batman's willpower. As a result, it had little opportunity to display the characteristics of a symbiont, such as taking over the host's body, congealing armor, rapid recovery, etc.
The Gray mist has a completely different nature from Venom, so Batman didn't realize that Shiller's ability to turn into mist came from a symbiont like Venom.
He assumed these abilities were like Constantine's magic, requiring human activation and control.
Previously, Batman had written about Constantine's weaknesses. Before casting magic, if you could break his limbs or silence him, making him unable to make any movements, most of the magic spells would fail.
The weakness of a mage has always been their physique: once they are severely injured and unable to perform precise actions, they would easily lose control and miss any chances of a turnaround.
By analogy, if Shiller was merely psychologically compromised before, and the agents found the right moment, now, his severely injured body may make him lose all resistance capabilities and plunge him into great danger.
Shiller announced himself as the Central American revolutionary organizer when he was arrested by the agents, most likely to cover up for Alfred. He probably thought his exposure was inevitable, so he opted to claim a significant identity to protect the safety of his important comrades.
Now, Batman understood that he wasn't racing against the agents, but time, or to be precise, racing against Shiller's rate of life loss.
Meanwhile, Shiller clutched his neck and sat next to the passageway. Scott ripped off the hem of his shirt to bandage Shiller.
"You nervousness exceeds my expectations, Agent," Said Shiller while pressing on his wound and wrapping the bandage around it. "If your hands shake any more, we will only meet in Hell."
Scott cursed and then said, "You're the craziest crazy person I've ever met! I don't understand what the hell you're trying to do?!"
"Me?" Shiller mockingly wrapped the bandage and used the gray mist to heal most of his wounds, leaving only some superficial wounds to continue bleeding. Sitting in the dark passageway, leaning against the cold, dry wall, he looked up at the ceiling and said:
"Agent, I have to say, the truth serum you used is highly concentrated. Don't you think it's a good time for interrogation?"
"Fuck the interrogation!" Scott looked at Shiller in frustration and said, "Is it time for interrogation? That damn Killer Croc and the batshit crazy in the Batman costume! What's going on with them?"
"Why are they chasing us? And how can we get out of here?" Scott kept taking deep breaths, trying to calm himself.
However, the underground passageway was not conducive to human survival. Being in such an environment for an extended period would put great pressure on a person's emotions. Scott felt as if his senses were amplified. Any slight movement would make him nervous.
"Don't be nervous, you should relax a little, like me." Shiller took out a cigarette from his suit pocket. Scott widened his eyes. Shiller just shook his head and said, "Where's the thing you used earlier to light it up?"
"Light my cigarette, or Mr. Agent. That way, I can recover faster and, as you wish, get out of this hellhole with you." Shiller still found speaking somewhat difficult. Although he spoke fast, there were long pauses between sentences. Amidst the flickering light from lighting the cigarette, Scott noticed that Shiller's hand holding the cigarette was shaking violently.
"How are you feeling?" Scott glanced at the fresh blood around his neck and said, "You better not die here, it would be better if you don't…"
"Don't worry, I won't die." Shiller coughed vehemently, instantly soaking the bandage with fresh blood that seeped out from the wound. His voice was hoarse and trembling, resembling an addict that Scott often encounters.
"It's just that the high dosage of barbiturates caused some spasms in my bronchus, making it hard to breathe. Besides, my heart rate is irregular and my body temperature has dropped about two degrees. If you could get me a shot of adrenaline, I think I would feel better."
Before Scott could speak, Shiller interrupted quickly: "But I must say, as a drug for interrogation, it does make me feel relaxed. My brain is urging me to say something …"
"What do you plan on saying?" Scott finally regained some composure. He sat opposite Shiller, watching the flicker of the cigarette in his hand, and said, "How you organized and led the revolution in Central America?"
"Let's not talk about the boring stuff." Shiller shook his head, strained his trembling arm to put the cigarette into his mouth. The shaking of his arm made his lips tremble concurrently. He had to bite his teeth to ensure the cigarette wouldn't fall out.
Consequently, his voice sounded as if it was squeezed out from the gaps between his teeth, somewhat garbled. He said:
"Perhaps, you've met many highly intelligent criminals who graduated from prestigious schools. Gifted and successful, they chose a life of crime without any external coercion or environmental pressure."