What the Slime Recognized
The reaction hit the hot spring harder than anyone expected. The water convulsed as if something underneath it had been struck directly in the core. Steam exploded upward, not hot enough to burn but violent enough to force everyone back a step. Aqua shouted in surprise, nearly losing her footing as the vial in her hands glowed faintly, the alchemy reacting exactly as Ruko calculated. Hans screamed.
It wasn't a sound made with a mouth. It was a vibration that traveled through the water, rattled the stone, and made everyone's skin crawl. The massive slime body recoiled, its surface warping and folding in on itself as the poison saturation destabilized. Sections of it lost cohesion, melting into useless sludge before snapping back together again. Kazuma stared wide-eyed. "Okay—yeah—that definitely worked."
Ruko didn't respond. He was already moving. Ignoring the burning ache in his body, he stepped closer to the water's edge, eyes locked on the writhing slime. His Insight was still active, though barely. Numbers, reactions, and probabilities blurred together in his mind. He knew he didn't have much time before the mental strain caught up with him.
"HANS," Aqua shouted, raising the vial higher. "PURIFY—!" "WAIT." Ruko's voice cut through the chaos sharply. Aqua froze mid-chant, startled. "What?!" Ruko didn't take his eyes off the slime. "Not yet. He's still compensating. If you release everything now, it'll disperse too fast. So right now just purify the spring again and again till I'll tell you to release it." Hans surged upward, forming a towering mass of translucent poison. Parts of the slime steamed where the alchemical reaction continued to eat at its structure.
Then, slowly, deliberately, the slime leaned forward. Toward Ruko. Darkness stepped forward instinctively. "Ruko—" "I'm fine," he said calmly, holding a hand out to stop her. Hans' surface rippled, then condensed into a more defined shape, looming just a few meters away. The slime's voice emerged again, lower this time, more focused. "So it was you." The words weren't loud, but they carried weight. Kazuma frowned. "What is it talking about?"
Hans ignored him. Its attention was fully locked on Ruko. The pressure in the air shifted, subtle but unmistakable. Ruko felt it immediately. His Insight flared one last time, feeding him a warning he already understood. Hans wasn't just reacting to the alchemy. It was reacting to him. "You don't belong here," Hans said slowly. "This world does not create beings like you."
Ruko didn't flinch. He stood straight, posture relaxed despite the tension crawling up his spine. "You're a slime poisoning a holy site. You don't get to lecture anyone about belonging and you sound just like Beldia too." Hans laughed, the sound bubbling through its massive body. "You think I'm talking about your strength? No. I've seen power before. Demon Generals wield it and beldia is not up to par with me. So we're not alike. Heroes abuse it. Gods waste it."
The slime leaned closer. "But you…"
Its voice dropped. "…you feel familiar." Aqua swallowed. "Ruko…?" Hans' surface rippled again, as if struggling to maintain form. "That presence. That hollow pressure. That wrongness layered over existence itself." The slime paused, then spoke with certainty. "You are from the same side as them." Silence fell. Ruko's heartbeat spiked for half a second—then steadied.
He didn't ask what Hans meant. He didn't deny it either. Instead, he spoke plainly. "You're overthinking things." Hans recoiled slightly. "You deny it?" "I deny that you get to use to shut the crap," Ruko replied calmly. "Whatever you think you recognize, it doesn't change the fact that you're losing control of life." The slime trembled. Hans hadn't expected that answer.
Kazuma hissed under his breath. "Why does it feel like we're missing some very important context?" Megumin tightened her grip on her staff. "I don't like the way it's looking at him." Hans pulled back, its body expanding again, unstable now. "Interesting. You don't fear being seen." Ruko's eyes narrowed slightly. "Fear doesn't help with problem-solving." That was when Hans made a mistake.
It lunged.
The water surged violently as the slime tried to engulf Ruko directly, ignoring the others completely. Darkness moved instantly, throwing herself in front of him—but Ruko was faster. "NOW," he said. Aqua didn't hesitate. "ALL OUT PURIFY!" The vial shattered in her hands, releasing a focused blast of divine energy directly into the destabilized core Ruko had calculated moments earlier. The water exploded with light. Hans shrieked. "N-No that's too much holy. I should get out of the spring!" It's too late, its body convulsing as the poison collapsed inward on itself.
Megumin shouted, "CLEAR THE AREA FOR A COUNTER ATTACK!" Hans is started to flee. And they managed to hold Hans at place till Kazuma dragged Aqua back as the slime began to disintegrate in chunks, massive sections evaporating under the purification. The waterfall behind them roared louder, ancient runes flaring faintly as the corruption was stripped away.
Hans screamed again—but this time, it wasn't confident. "This isn't over," the slime snarled, its body breaking apart rapidly. "They will notice you and you won't be able to witness." Ruko watched calmly as the slime's form collapsed. "Let them. Whoever your saying to." The final surge of purification ripped through Hans' core. With one last violent tremor, the Demon General dissolved completely, leaving behind only steaming water and silence.
The hot spring went still. Aqua collapsed to her knees, panting. "I—I did it. I really did it." Kazuma stared at the water, then at Ruko. "You're explaining that later." Megumin exhaled shakily. "Please tell me that was the last surprise for today." Ruko didn't answer right away. His legs finally gave out, and he dropped to one knee, breathing heavily. The strain of Insight hit him all at once, his vision dimming at the edges.
Darkness caught him before he fell fully. "You pushed yourself too far," she said quietly. "I know," Ruko replied, voice steady despite the exhaustion. "But it worked." As the steam cleared, something shimmered near the base of the waterfall. A faint glow. Ruko looked up—and felt it immediately. There was runes carved into the stone pulsed softly, responding to his presence.
The water parted just enough to reveal a dark fragment embedded in the rock, humming with a familiar pressure. "Guys I wanna go check the waterfall myself, so wait here for me." "Seriously! you just badly injured so you should rest." Kazuma being worried of what Ruko is doing with himself. "I'm not gonna die. Just what is at the waterfall. That's all." "Hm.. hmm. Gah! OK ok you can go but don't hurt yourself more that you can heal."
"Hmph." Ruko nodded and headed at the parted waterfall, while observing the runes embedded the rock around the cave. "It's the same as the ruins from parted side of Axel. But i wonder why there's runes and relics in Konosuba in the first place?" The further ruko go he stumbled upon the second sha-obelisk relic fragment. The moment his fingers brushed it, a flash tore through his mind— Laughter. Not loud. Not cruel. Just Amused.
Shadows shifting in a place that didn't obey distance or light. Then— Nothing. The memory vanished instantly, sealed away, leaving only a dull ache behind his eyes. Ruko exhaled slowly. Whatever that was… he wouldn't remember it for another day. Behind him, the others were already celebrating their survival, unaware of what had just brushed against his mind—or what Hans had truly seen. And far away, something else had noticed him too.