The darkness was absolute. Rin couldn't see his own hand in front of his face.
Around him, the crowd's noise became muffled, distant, as if Vera's shadow domain blocked even sound. He heard movement in the darkness, something large circling him with predatory patience.
"Malachar," Rin thought through their bond, keeping his mental voice calm despite his racing heart.
"I see it," the demon lord responded. "Interesting. This darkness isn't natural. It's a constructed space, a miniature dimension overlaying reality. Clever girl."
The Shadow Drake struck without warning. Rin felt the displacement of air in a heartbeat before claws raked across his shoulder. Pain exploded through him as he stumbled backward.
"First hit!" Dante's voice called from somewhere outside the darkness.
Blood soaked through Rin's uniform. The wound wasn't deep, but it burned with unnatural cold.
"You should surrender," Vera's voice echoed around him. "In my domain, you're helpless. Your demon can't fight what he can't touch."
Rin focused on his summoning mark. "Malachar, manifest!"
Crimson mist erupted from his shadow, coalescing into the demon lord's form. But something was wrong. Malachar's usual burning eyes were dimmed, his outline less distinct, as if the darkness was suppressing his presence.
"This shadow is trying to smother me," Malachar growled. "It recognizes me as a rival of darkness and is actively resisting."
The Shadow Drake attacked again, phasing through Malachar's attempted block and slamming into Rin's side. He flew backward, hitting the arena floor hard.
"Second hit!"
Rin coughed, tasting blood. Through their bond, he felt Malachar's frustration. The demon lord was powerful, but in this constructed darkness, his movements were restricted, his power dampened.
"We need to change the environment," Rin thought desperately.
"How? The girl controls this space completely."
An idea sparked. Dangerous, possibly stupid, but their only chance.
"What if we don't fight her darkness?" Rin pushed himself to his feet, ignoring the pain. "What if we make it yours instead?"
He felt Malachar's surprise, then understood. "That would require you to channel a massive amount of my power. The corruption marks will spread."
"I know."
"You could lose yourself."
"I know!" Rin's voice echoed in the darkness. "But if we don't do something, we've already lost. So let's show them what a real demon lord can do."
A moment of silence. Then Malachar laughed, that cruel sound that had terrified the academy on the first day.
"Very well, boy. Let's paint this arena in proper darkness."
Rin pressed his hand to his summoning mark and opened the bond completely. Power flooded into him, dark and vast and ancient. His arm exploded with pain as the corruption marks spread like wildfire, racing up his shoulder, across his chest, crawling up his neck.
"What's happening?" Vera's voice lost its confidence. "What are you doing?"
Crimson light burst from Rin's mark, cutting through the shadow domain. Malachar's form became solid again, his armor gleaming with restored power. But more than that, the darkness itself began to change.
Vera's constructed shadows, cool and silent, started mixing with something older. Hotter. Hungry. The arena filled with the scent of sulfur and burning stone.
"You think you know darkness?" Malachar's voice boomed, no longer diminished. "Let me educate you, girl. What you command is shadow, the absence of light. What I am is Abyss, the darkness that existed before creation itself!"
The Shadow Drake shrieked as Malachar's presence overwhelmed the domain. Vera's carefully constructed space began collapsing, her shadows retreating from the crimson darkness spreading from Rin's position.
Through the bond, Rin could see everything. The drake's position, Vera's location, even the shocked faces of the crowd as the darkness became transparent to his perception.
"There you are," Malachar said, and lunged.
The Shadow Drake tried to phase to intangibility, but Malachar's blade followed it into that immaterial state. The demon lord moved between dimensions as easily as walking, his sword connecting with the drake's ethereal form.
The creature materialized involuntarily, solid and vulnerable. Malachar's kick sent it crashing across the arena.
"Third hit!"
Vera's composure shattered. She made desperate hand signs, trying to reassert control over her domain, but the darkness no longer answered her commands. It belonged to Malachar now.
The Shadow Drake recovered and attacked in a fury, claws and fangs and lashing tail all striking at once. But Malachar moved like he could see the future, dodging or deflecting every attack with minimal effort.
"Your drake is fast," Malachar observed, almost bored. "But predictable. Shadow beasts always rely on the same tactics: hit and run, phase and strike, overwhelm with speed." He caught the drake's neck mid-lunge. "I've killed hundreds of your kind."
He slammed the creature into the ground. Once. Twice. Three times.
"Fourth hit! Fifth hit!"
The Shadow Drake dissolved, unable to maintain manifestation. Vera fell to her knees, the backlash of the broken summon hitting her hard.
"Match concluded," Dante announced, his voice tight. "Winner: Rin Eldraven."
The darkness evaporated instantly. Light flooded back into the arena, and Rin saw the crowd's expressions. Shock. Fear. Awe.
Then he saw his own arm.
The corruption marks had spread past his shoulder, across his chest, creeping up the right side of his neck. Black geometric patterns covered nearly a third of his visible skin, pulsing with dark energy.
"Rin!" Kira's voice, horrified.
Malachar dissolved back into shadow, and the sudden absence of power nearly made Rin collapse. Professor Corvin rushed into the arena, her face pale.
"Eldraven, your arm!"
"I'm fine," Rin lied, pulling his sleeve down. But it was too late. Everyone had seen.
Dante descended from his position, his expression unreadable. "An impressive victory. But also a concerning one." He gestured to Rin's concealed arm. "Those marks. They're corruption stigmata, aren't they? Signs that your bond is changing you."
The arena went silent.
"It's under control," Rin said.
"Is it?" Dante's gaze was piercing. "You just channeled enough power to overwhelm a Gold tier summon's constructed domain. That's not normal for any student, let alone an unranked first year." He turned to address the crowd. "Let this match serve as both demonstration and warning. Power has consequences. Remember that."
He left, his message clear. Rin had won, but at a cost everyone could see.
Medical staff helped Vera from the arena. As she passed Rin, she whispered, "That darkness... what are you?"
Rin had no answer.
In the medical wing, Professor Corvin examined his arm with various diagnostic tools. Her expression grew grimmer with each test.
"The corruption has accelerated dramatically," she said. "It's now covering approximately thirty percent of your body. Another manifestation like that, and it will reach fifty percent."
"What happens at fifty percent?"
"We don't know. There's no documented case of someone bonded to a Nexus entity. But based on other corruption studies..." She met his eyes. "You'll begin losing your human reasoning. The demon's instincts will start influencing your thoughts. Eventually, you won't be able to tell where you end and Malachar begins."
"How do I stop it?"
"You can't. You can only slow it." She pulled out a silver bracelet engraved with runes. "This is a containment seal. It will suppress some of your bond's power, and limit how much energy you can channel. It won't reverse the corruption, but it might prevent it from spreading further."
Rin took the bracelet. It was cold and heavy. "Will I still be able to fight?"
"Yes, but not at the level you just demonstrated. You'll need to rely more on strategy and less on raw power." She paused. "Rin, I need you to understand. The path you're on is dangerous. Every time you use Malachar's power, you risk losing more of yourself. Eventually, there may not be anything left to save."
"I understand."
But did he? Rin looked at his marked arm, at the patterns that now permanently decorated his skin. He'd won the match, proving he could compete with the academy's elite. But the price was becoming more obvious with each battle.
Kira arrived as Professor Corvin left. She stopped in the doorway, staring at Rin's exposed arm.
"It's worse than I thought," she whispered.
"I'm still me, Kira."
"For now." She came closer, her usual enthusiasm dampened by worry. "But what about after the next fight? And the one after that? How many more battles until you're more demon than human?"
"I don't know. But I don't have a choice. If I don't fight, I'll be expelled. And if I'm expelled..." He trailed off.
"The bond will kill you," Kira finished. "Soul Resonance bonds require proximity. If you're separated from the academy's dimensional anchors, the strain would tear you apart."
They sat in silence for a moment.
"There has to be another way," Kira finally said. "Some method to stabilize the bond, prevent the corruption from spreading. Let me research it. I'll find something."
"Thank you."
After she left, Rin was alone with Malachar's presence.
"The girl is right to worry," the demon lord said. "The corruption is accelerating. But there's something I haven't told you."
"What?"
"The marks aren't just corruption. They're also adaptations. Your body is changing to accommodate my power, yes, but that also means you're becoming stronger. Faster. More resilient." A pause. "There's a point where corruption stops being a weakness and becomes an evolution."
"At the cost of my humanity."
"Is your humanity worth keeping if you're dead? If you're expelled and the bond tears you apart?" Malachar's voice was matter of fact. "Survival requires sacrifice, Rin. The question is: what are you willing to sacrifice to live?"
Rin had no answer.
He fell asleep in the medical wing, exhausted and aching. In his dreams, he stood in Malachar's ruined throne room again, but this time, the demon lord's younger self was there.
"You're changing," dream Malachar said. "Soon, you'll have to choose. Remain human and weak, or embrace what you're becoming and survive."
"Those can't be the only options."
"In my experience, they always are."
Rin woke at dawn, the bracelet on his wrist cold and restrictive.
The monthly ranking tournament was tomorrow.
And he had no idea how much of himself would remain by the time it ended