Infinite Undying [Post-Apocalypse LitRPG]

"You have incredible talent, Lena! You can do so much with that power! The Tribute Core... we need to unlock its full potential. With the Sigil your parents left you, you'll become an extraordinary Hunter. You'll become someone truly gre..."

The voice of an eight-year-old child echoed through the haze of his fading consciousness, breaking apart into meaningless fragments.

Madou felt as though he had been trapped in this same state for hours, maybe even days, ever since the curse had struck him.

The curse was not only rotting away his chest, it was also slowly tearing his consciousness apart. It felt as though his eyes were only half open, while his mind drifted endlessly between awareness and darkness.

There was an attack.

Everyone was fighting outside.

How powerful was the enemy? How massive was the monster? Why was the entire cave shaking this violently?

Madou struggled to stay awake. He fought with everything he had just to open his eyes.

But he could do nothing.

His body was completely locked in place, refusing to respond no matter how desperately he tried. He caught scattered pieces of what was happening, their screams, the sounds of battle, broken moments that never fully came together.

Yet all of it felt like a dream, suspended somewhere between consciousness and oblivion.

Madou kept fighting.

He felt as though he was standing at the edge of a cliff, where the slightest lapse in focus would send him plunging into the endless darkness below.

He knew exactly what would happen to him if he let himself fall.

This wasn't just some fucking nightmare.

There would be no coming back. His soul was already being dragged into that bottomless void, slowly losing itself to its pull. Once it was gone, whatever had been trying to claim his body all this time would finally make it its own.

"Your body, Zeph..."

"Y-your whole body is rotting..."

"I-I can't stop it... It keeps spreading..."

"W-what do I do...?"

That voice...

Madou knew it instantly.

Lena.

LENA!

What's happening?! Wake me up, Lena!

I DIDN'T COME TO THIS PLACE JUST TO LIE HERE, HIDDEN AWAY UNDER YOUR PROTECTION WHILE ALL OF YOU RISK YOUR LIVES OUT THERE!

GOD DAMN IT! GOD DAMN IT! LENA!

WAKE ME UP!

WAKE UP THIS PATHETIC MAN WHO COULDN'T EVEN DO HIS JOB AS YOUR PROTECTOR!

LENA!

HOW AM I SUPPOSED TO FACE YOUR PARENTS WHEN I SEE THEM IN THE AFTERLIFE?!

I'M A USELESS BIG BROTHER!

I'M WORTHLESS!

LENA!

Madou had to wake up. He knew what was happening. A great war was raging. They were suffering. Zeph was badly wounded.

Zeph was badly wounded!

HE WAS NEVER SUPPOSED TO COME HERE!

ZEPHION, I WARNED YOU! YOU STUBBORN IDIOT!

I have to wake up!

Shards of light slowly slipped into Madou's vision as he felt a freezing cold pierce deep into his heart, a heart that had almost forgotten how to beat.

His sight slowly returned. Everything was still blurred, but he began to make out what was happening. There was a golden light. It was a light he recognized without the slightest doubt.

It was Lena's Legendary-grade Sigil, an extraordinary inheritance left behind by her parents and embedded within her.

Lifeline. Lifeline channeled her mana into healing, closing wounds, mending broken bones, and stopping blood loss. It was an incredible Sigil.

But her Core... her true Core ability, The Tribute Core, allowed her to turn anything she possessed into fuel. Whether by choice or simply by her own will, it demanded a price.

She would give up anything if it meant pushing that Sigil to its absolute limit.

Madou's vision returned just enough for him to see Zephion's condition.

The boy lay sprawled across the ground. Half of his face was destroyed. His arm. His stomach. His thigh.

Damn it, Zeph... How are you still alive in that condition? You're in even worse shape than I am. I'm practically an undead corpse, lying here without the strength to move.

Zeph... you were never supposed to be here! I was supposed to protect you! I was supposed to protect both of you!

Instead, I'm lying here like some useless fool who can't do a damn thing!

How pathetic.

I FUCKING HATE MYSELF!

Madou lay there, completely still, forcing himself to endure. He screamed at the top of his lungs! In complete silence. It was as if his soul was tearing itself apart against invisible chains.

He had to move! He had to get up! No one had the right to control him! To control this body.

No matter the situation. Even as an undead! Even in this state! Half dead! No matter what happened. He would stand. He would become the nightmare of those walking corpses! They had to know that his will was far stronger than theirs!

A powerful shockwave burst out, as if it shook the entire cave.

What was that?

Lena glanced toward Madou for only a brief moment. But...

LENA!

LENA! LENA! LENA!

Lena...

She turned back and continued her healing. Even so, there was one thing that deep inside, Madou had already expected would happen.

Lena kept forcing the healing to continue. Until, little by little, the curse began to spread into her own body.

Her left hand had already turned dark. Rotten. Her face had become pale, dry, and deeply wrinkled. The skin grew so thin that parts of her skull were beginning to show beneath it.

Lena.

The fingers that had always been busy cooking, and taking care of everyone, had now withered until only thin skin clung to the bones beneath.

She was giving everything she had. She was pouring every last bit of herself into restoring Zephion.

Lena!

The golden light continued to shine as Zeph's body visibly regenerated. The dried blood disappeared. Fresh life returned to his body. The deep gashes across his face, stomach, thighs, and arms slowly closed until they were whole once more. A healthy body stood there again.

And Lena?

She now looked like nothing more than an empty shell whose life had already been drained away, as the final traces of that golden light gradually began to fade.

Perhaps that was the last light of life she had left.

The next moment, the girl's body collapsed weakly to the side. At the same time, Zeph suddenly woke and stared at both of his hands in confusion.

Zeph turned toward Lena.

Then his face froze in shock.

His face trembled. Both of his hands shook as they slowly reached toward Lena's fragile body.

Then… A scream echoed through the cave.

Zephion let out a deafening roar. His voice thundered throughout the cramped cavern. At the same time, heavy impacts continued to echo from outside.

The other two were still fighting against the horde of undead without pause.

Yet Zeph kept screaming. Crimson and black energy burst violently from his body. It blazed around him like raging fire. Flames formed from shadow and crimson light wrapped around his entire body.

Then the energy compressed. It grew denser and denser.

Within moments, the figure sitting there was no longer Zephion.

Instead, someone clad in full armor sat in his place. The armor looked terrifying, with jagged edges across several parts of it. Crimson energy burned through the eye sockets of the mask he wore.

And the sword lying beside him… It was solid. Nothing like the transparent weapon the boy had shown before.

Zeph! You may have awakened your ability! But you can't do this alone!

The next instant, the boy shot out of the cave at incredible speed. The crystal lamp fell to the ground, rolled across the stone floor, and finally came to a stop right in front of Lena's motionless face.

That face.

That bright, cheerful face.

The face Madou was supposed to protect.

[Your overwhelming emotional surge and unyielding will have surpassed the limits of your Core.]

[The impossible has become possible. Your Core has responded to your determination and achieved a breakthrough.]

[Vanguard Core embodies those who never retreat. Its bearers stand at the front line, endure impossible burdens, and continue fighting even when their bodies can no longer move.]

[Your resolve has fulfilled the Core's true requirements.]

[Vanguard Core has achieved a breakthrough.]

[Rank Up Complete.]

[Level Up!]

[Level 21]

[New Sigil Acquired]

[The Undead Curse attempted to seize control of your body. However, your will has overwhelmed the curse instead. The curse has been subdued and permanently integrated into your body.]

[Rare-Grade Curse-Type Sigil Acquired: Hollow Rot]

A deafening impact rang through the cave.

Cracks spread across the cave floor as his fist slammed into the ground with overwhelming force.

Madou pushed himself upright.

His crimson eyes snapped open.

"You damned walking corpses!" he roared. "I'm going to kill every last one of you!"

**

A figure clad in pitch-black armor emerged from the fading crimson flames.

An oversized sword rested across his shoulder as wave after wave of energy erupted from his body, sweeping across the battlefield and forcing the surrounding undead to stagger back.

"Stay behind me. Take cover inside the cave. I'll finish this."

Brann and Koka lay sprawled near the dark warrior's feet. Their faces were covered in blood, their bodies bruised and battered. Both of them turned pale when they heard the deep, echoing voice coming from within the armor.

"Who are you?!"

"Zeph! What happened to you?!"

"Enough. Let's rest for now. Leave this to him. We can trust Zeph."

"Help me. My legs have completely given out. I can't even stand anymore."

The two men then struggled toward the cave with what little strength they had left.

A moment later, another figure shot out from inside and came to a stop beside the dark warrior.

It was a man whose face was half consumed by black rot. His chest had also turned completely black, while his crimson eyes burned with an eerie glow. Dark metal knuckles covered both of his fists.

The dark warrior turned toward the half-undead man.

"Madou?" the heavy, hoarse voice called.

"Got a plan, Zephion?"

Zeph turned back toward the battlefield. He lowered the tip of his sword toward the approaching horde as the undead charged once more.

Then the Undead Knight stepped out from the line of trees. The surrounding undead immediately parted to clear its path.

Finally... the real boss had arrived.

"The plan is..." he said.

He raised the oversize sword.

"Kill them all. Leave nothing standing."

Madou grinned. "Sounds like a good plan."

They both dropped into a low stance.

The next instant, a deafening boom echoed across the battlefield. The ground beneath their feet fractured as they exploded forward.

Zeph shot forward at incredible speed. Not just fast, but many times faster. Stronger. His kicks, his movements, his precision. The sword. It felt so heavy, yet somehow it moved exactly as he commanded, as if it answered every call without hesitation.

He should have died earlier, maybe from a slash to the neck. But instead, he felt stuck between awareness and losing himself, as if something was pulling him down into an abyss, even though he knew his body was not completely dead yet.

What kind of terrifying feeling was that? It was far worse than the time he had died and fallen into the endless abyss.

Then, in that moment, a hand wrapped in golden light reached out to him. A woman appeared, glowing like a golden avatar, her long hair flowing, a pair of wings spreading wide as she pulled him in. She lifted him, carrying his fading consciousness back to the surface.

Lena had done all of this for him. Lena had sacrificed herself for him. Lena!

Zeph clenched his teeth and gripped his sword tightly.

“I won’t let your sacrifice be wasted! I will crush everything in my path, and I swear I will fulfill your promise, Lena.”

“Zephion…” Those were the last words he heard from the girl.

“You have to wake up. You have to keep going. You have to make it out of this place. I know you can do it. I know you have more strength than you realize.”

“I leave my final wish to you. Please, when all of this is over, take Madou out of here and bring him to his father.”

"I know how painful it is to wait without knowing when it will finally end. I know Madou will endure. I know he's strong. I know he'll make it through."

“Zephion, Madou, I know you both can finish this.”