Arthur floated above the newly restored hellscape, his silver aura still blazing but noticeably dimmer than before. The battle had taken its toll.
He glanced at his HUD. Six minutes remaining.
Fifty feet away, the air shimmered and twisted. Mephisto materialized, smoothing his suit. The demon looked exhausted despite his instant regeneration. The cosmic attacks had drained something that healing couldn't restore.
"Mephisto," Arthur called out. "Do we have to do this?"
Mephisto raised an arrogant eyebrow. "Do what? You dying? I'm afraid that's the highlight of my evening."
"We don't have to be enemies," Arthur said, his tone steady, devoid of fear. "You've seen my power. You know that even here, in the heart of your absolute domain, I can hurt you. And you know you can't stop me from leaving whenever I choose."
Mephisto's smile didn't waver. "And?"
"And on Earth, the balance shifts," Arthur continued. "On Earth, I am the apex. If we continue this feud, I will dedicate my life to ruining yours. I will hunt down every contract holder you have. I will exorcise every demon you send. I will dismantle your influence brick by brick until the name Mephisto is forgotten by mortals."
Mephisto's eyes narrowed. "Is that a threat?"
"It's a promise," Arthur said coldly. "Unless we make a deal. I leave you alone. You leave my family alone. You never look at my son. You stay in your lane, and I stay in mine."
Silence stretched over the burning landscape. The magma bubbled below, the only sound in the standoff. Mephisto tapped his chin, looking thoughtful.
Then, slowly, the Devil smiled.
"No."
"Mephisto—"
"Your son is worth more than peace." The demon's eyes gleamed with a hunger that transcended mere power. "I would give up everything for that potential. All my pawns. All my schemes. All my millennia of careful planning."
He began to pace, circling Arthur like a shark scenting blood.
"You'll grow old, Hayes. You'll make mistakes. You'll grow weak." His voice dropped to a whisper that carried across the distance, intimate and terrifying. "And when you do, I'll be there. Waiting. Watching."
Arthur's hands clenched into fists.
"I'll take him while you sleep," Mephisto continued, savoring the words. "Or while you're distracted by some other threat. Or perhaps I'll wait until you're on your deathbed, too frail to lift a finger to stop me."
"That will never happen."
"It will." The demon's smile widened, revealing too many teeth. "And then I'll raise him as my own. I will twist that magnificent potential toward my purposes. I will turn your beloved son into my greatest weapon."
"Mephisto..." Arthur warned, his voice low.
"I'll make your wife watch," Mephisto pressed on, his tone almost gentle now, mocking. "I'll let your daughter see her brother become a monster. I will savor your family's destruction piece by piece, moment by moment."
He leaned forward, eyes blazing with anticipation.
"And the best part? The absolute best part?" Mephisto ran his tongue over his lips. "He'll hate you for it. He'll blame you for failing to protect him. He'll channel all that power into destroying everything you built, everything you loved."
His smile was pure malice.
"It's going to be so much fun, Hayes. I've been alive for eons, and I can honestly say I'm looking forward to this more than anything I've experienced before."
Something inside Arthur snapped.
It wasn't a loud snap. It was the quiet, terrifying sound of a man's control over his emotions breaking.
The anger didn't burn hot; it froze. It turned his blood to ice and his mind to a single, singular point of destruction.
He looked at the smiling Devil.
He didn't think about strategy. He didn't think about anything. He just wanted this thing gone.
His hand rose without conscious thought. His finger pointed directly at Mephisto's smiling face.
And two words emerged from his lips, powered by fury beyond anything he had ever felt.
"Avada Kedavra."
A beam of green light erupted from his finger.
It wasn't the thin jet of light used by Voldemort. Boosted by the Arcane Mage state, it was a rushing river of death energy, zooming toward the Hell Lord.
Mephisto felt the magic. He sensed the intent.
"Soul magic?" He scoffed. "Please."
He raised a hand, conjuring a barrier of condensed reality. A shield made of the dimension itself.
The green light hit the barrier and stopped.
Mephisto smirked. "You cannot kill me with—"
FLASH.
On Arthur's chest, beneath his suit, the Deathly Hallows mark ignited once again.
It didn't just glow; it screamed. A pulse of ancient, cold power surged through Arthur's body, feeding directly into the spell.
The green light didn't grow larger. It turned white.
CRACK.
Mephisto's barrier shattered like cheap glass.
The Hell Lord's eyes went wide. For the first time in eons, he felt true terror.
The beam hit him square in the chest.
There was no explosion. No heat. Mephisto's body was simply hurled backward as if kicked by a god. He slammed into the obsidian ground and skidded for a hundred yards, plowing through rock and bone.
He lay there. Motionless.
Silence reclaimed the realm.
Arthur stared, chest heaving, the red haze of rage slowly fading.
Had that actually worked? Had the combination of the Killing Curse and Death's Mark actually—
The body vanished.
Mephisto emerged from the shadows thirty feet away.
He was pale. Paler than usual. His hands were shaking uncontrollably. He touched his chest, where a black, necrotic mark in the shape of a triangle was slowly, painfully fading.
He looked at Arthur with wide, frantic eyes.
How could a mortal control that? Mephisto's mind raced with panic. That power... it severed my link to the realm for a microsecond. If he was any stronger... if he truly knew how to wield Death's power...
He forced a smile onto his face. It was brittle, terrified, but he forced it.
"Is that it?" Mephisto laughed, though the sound was thin and wavering. "A killing curse? Against me? Oh, Hayes... you really are desperate."
He taunted the mortal, mocking him to hide the tremor in his hands. He needed to kill Arthur now. Before the wizard realized what he had almost done.
Arthur stared at him. The hope faded from his eyes.
"It didn't work," Arthur muttered to himself. "Even that... didn't work."
For a long moment, neither of them moved.
Suddenly, Arthur felt a tremor in his core. He checked the HUD. Only two minutes left.
"Final chance," Arthur said, his voice flat. "We can still have peace, Mephisto."
"No," the demon replied, his confidence returning as he sensed the shift in Arthur's energy. "I win."
Arthur raised an eyebrow.
"Your special state limit has been reached." Mephisto's smile was thin but knowing. "I can feel it straining. It will end any minute now."
Arthur said nothing.
"Once it ends, you'll be defenseless. Drained. Standing in the heart of my domain without your precious transformation." Mephisto spread his arms. "I just have to wait you out."
"And then what?" Arthur's voice remained calm. "I can still leave. Open a portal, step through, recover on Earth." He shrugged. "Then come back for another round."
Mephisto's smile flickered.
"There should be side effects," the demon pressed. "A state that powerful doesn't come free. You'll need time to recover. Days, perhaps. Weeks."
"What if there are?" Arthur crossed his arms. "Even weakened, I'm more than enough for you on Earth. Your avatars are shadows of your true power. I've destroyed them before."
"You can't protect your family every moment."
"I don't have to. There are other protectors on Earth." Arthur's eyes hardened. "Let's face it, Mephisto. You cannot win this."
The demon was quiet for a long moment.
Arthur checked his HUD. One minute remaining.
Time to go.
"This has been fun," Arthur said, turning away. "But I have a family waiting for me."
He raised his hand to cast a portal.
"Wait."
Something in Mephisto's voice made Arthur pause.
"You can leave if you want," the demon said slowly. "Go back to your precious Earth. Recover from your transformation. Hug your children."
His smile turned cruel again.
"But be ready for what comes next."
Arthur's eyes narrowed. "Meaning?"
"Phantoms." Mephisto spread his hands theatrically. "Endless waves of them. They'll attack you. Your wife. Your children. Your friends."
"I'll destroy them."
"Yes. You will. Again and again and again." The demon's voice dropped, becoming silky and poisonous. "But I have unlimited phantoms, Hayes. I can play the numbers game. The timing game. I just need you to slip once."
Arthur turned to face him fully.
"Do we have to go to this extent, Mephisto?"
"Yes." The demon's voice was absolute. "You're a threat I must kill in the bud. Your power. Your potential. Your children's potential." He shook his head. "I will not allow the Hayes bloodline to grow beyond my ability to control."
"I'm offering you peace."
"And I'm rejecting it." Mephisto's form began to grow again, power gathering for the final assault. "Leave if you want, wizard. But know that the moment you step through that portal, the war begins in earnest."
Arthur stared at him for a long moment. Then he sighed.
"You leave me no choice."
Mephisto frowned. "What choice?"
Arthur raised his hand.
On his fingertips, a blue stone appeared. Not a crystal. Not a fragment.
The Space Stone. The real one.
"I didn't want to do this," Arthur said, his voice heavy with regret. "For one, the damage it will cause to my body is severe. And for another... because this fate is worse than death. Something I wouldn't wish even upon my enemies."
He looked at Mephisto with pity.
"But you threatened my family."
Arthur floated upward. The stone began to glow, blue light spreading across his fingers, up his arm, enveloping his entire body. A translucent blue dome of energy expanded around him, isolating him from the realm.
"What are you doing?" Mephisto asked, unease creeping back into his voice.
No reply.
Instead, the whole realm started glowing blue.
Mephisto felt it instantly. A sudden, crushing claustrophobia. The infinite connections to other realms - to Earth, to other planets, to other dimensions - had disappeared. He could not feel them anymore
"What..." Mephisto stopped. He looked at the fake sky, which was rapidly hardening into a solid, unmoving barrier. "What are you doing?!"
He tried to open a portal to outside Hell.
Blocked.
He tried to shift to a pocket dimension.
Blocked.
"You can't!" Mephisto screamed, realizing the horror of what was happening. "You cannot isolate me and my realm!"
He lunged for Arthur. "STOP!"
He tore through the air, his claws reaching for the wizard. He struck the blue dome surrounding Arthur.
And passed right through it.
It was like Arthur was in a different dimension entirely. A ghost haunting the throne room.
Mephisto turned, grabbing at the air where Arthur floated. "Wait! I agree to your peace deal! Stop!"
"Too late," Arthur whispered.
The blue light engulfed the entire horizon. The cosmic lock clicked shut.
"I can't kill you," Arthur rasped, his voice weak but echoing with finality. "And I can't stay here to fight you forever."
"NO!" Mephisto roared.
He understood now. He was being trapped. Isolated. Cut off from the souls he craved, the games he played, the manipulations that had occupied his existence for millennia.
Alone in his kingdom with no one to torment but himself.
"Enjoy your kingdom, Mephisto," Arthur said.
The Space Stone flared, tearing open a blue portal, the only way out.
"Because you're the only one who's ever going to see it."
"HAYES!"
Mephisto gathered every scrap of power he possessed. Hellfire, shadow, and pure demonic rage compressed into a single devastating blast. He hurled it at the wizard with a scream of desperation.
Arthur didn't dodge.
He simply stepped backward into the portal, letting the blue light carry him away.
"Bye."
The portal zipped closed in a microsecond.
The blast hit empty air.
—
Mephisto stood alone in the ruins of his throne room.
He reached out with his senses, frantically probing the boundaries of his realm.
Walls. Hard, impenetrable walls of folded space. The Space Stone, powered by a wizard in his prime state, had rewritten the coordinates of Hell itself.
He was locked in.
The Lord of Hell threw his head back and screamed, a sound of pure, impotent rage that shattered the remaining sky, echoing forever in a box of his own making.