Reincarnated As Poseidon

The Underworld was never silent.

Even in death, there were whispers. The groans of shades as they shuffled through obsidian gates, the scrape of skeletal ferries moving across black rivers, the sighing wind that carried centuries of prayers left unanswered.

Here, under the crushing mantle of the earth, the domain of Hades remained unchanged since the dawn of time.

But tonight, it stirred.

In the deepest pit of the Necropolis, where the flames of Phlegethon burned a crimson scar across the void, the God of the Dead sat upon his throne.

Hades did not move often. He did not need to. His presence was enough to still the restless dead. A crown of iron rested on his brow, dark and simple compared to the garish laurels of Olympus. His eyes—two pits of molten gold—surveyed the realm without emotion.

Yet when the tremors came, his gaze sharpened.

The tremors were not earthquakes. The Underworld had withstood storms, meteors, and divine wars without ever quaking. But this was different. This was pressure from the sea bleeding into the bones of the earth.

Poseidon's will.

Hades leaned forward slightly, his iron hand resting against the throne.

"So," he murmured, his voice like iron scraping stone, "the sea rises again."

A ripple passed across the chamber. Spectres froze mid-step. The guardians—three-headed Cerberus among them—lifted their heads as though hearing something deep and primal.

One of the Furies appeared, wings cloaked in shadow, kneeling at his feet. Her voice trembled though she was forged from fury itself.

"My lord… the river Styx swells. The dead cry out. They hear his call."

Hades's expression did not change, but inwardly, he understood the weight of those words. If even the dead stirred at Poseidon's awakening, then the world above was already far beyond repair.

He remembered the last time Poseidon's shadow loomed. Not Thalorin—the abyssal hunger that the other gods so feared—but Poseidon himself, in the age before Olympus was secure.

There had been a pact.

Zeus had drawn the skies, Poseidon had claimed the seas, and Hades—himself—had taken what none wanted: the Underworld.

It was balance, and for an age it worked. But Hades had not forgotten the look in Poseidon's eyes when the division was made. The god of seas had accepted, but not willingly. His heart had raged with storms ever since.

And now, after centuries of silence, Poseidon rose again, shaking both sea and death alike.

Hades closed his hand into a fist. "The council above will act. They will fear him. They will hunt him. And when they do…"

He let the thought trail, though the chamber filled with the echo of inevitability.

The other gods would make war. And war always sent its harvest downward.

The Underworld would swell.

A gate of bone cracked open. From it stumbled a mortal soul—not the shade of a farmer or soldier, but a burning presence wrapped in chains of fire. This was no ordinary dead.

The spirit knelt before Hades, gasping though it no longer had lungs. "He calls… even here. The sea god calls."

"Who sent you?" Hades's tone cut like ice.

The spirit looked up, its eyes filled with terror. "No one. The tide itself dragged me down. He whispers in the currents of Lethe, twisting memory. Even the dead remember him."

That… was impossible. Lethe was the river of forgetting. Nothing endured within it. Yet if Poseidon's influence reached so far that even memory could resist oblivion, then the seas of both life and death were bending to his will.

Hades sat back slowly. A god who touched both the living and the dead was no mere threat to Olympus. He was a threat to him.

Later, in the Hall of Iron Flame, Hades summoned his closest lieutenants. The Furies, Cerberus, and Thanatos himself—the embodiment of death—stood before him.

"The sea has awakened," Hades declared. "The world above quakes. Already the council sharpens their blades. But mark this: the balance does not serve us. If Poseidon rises unchecked, Olympus burns. If Olympus strikes him down, the earth will still bleed. Either way, death fattens."

Thanatos tilted his head, black wings brushing the stone. "Then you would watch? Harvest?"

The question was blunt, but Hades did not flinch.

"I would weigh," he said. "The sea god was never my enemy. Zeus would see him chained, Athena would see him undone, and Ares would gladly feed wars upon his corpse. But if Poseidon rises as more than himself—as something deeper, something ancient—then even death is not untouched."

The Furies hissed. Cerberus growled. The Underworld trembled faintly again.

"He calls," Thanatos whispered, his golden mask turning slightly toward the ceiling. "Even now. He does not fear you, lord. He invites you."

At that, Hades's mouth twitched—just slightly, the ghost of a smile.

"Invites me, does he? Then he has not forgotten the pact."

Hades rose from his throne for the first time in what felt like an age. The chamber dimmed as shadows pooled at his feet, stretching outward across the obsidian floor.

"If I choose, I could join Olympus and strike him down," he said, voice echoing like a tomb. "But the others would never grant me glory for it. They would use me as a weapon, then cast me back to my pit."

He turned, iron cloak sweeping behind him.

"Or… I could hear him. If Poseidon is no longer only himself—if the sea has truly become the abyss—then perhaps death and abyss may share a table."

A silence followed his words, broken only by the drip of black water into Phlegethon's flame.

The Furies shivered. Thanatos lowered his head.

"Then," Hades murmured, "we shall watch. For the world above is already at war, but the Underworld has yet to declare its hand."

In the mortal realm, the drowned cities whispered. Those who had died in Poseidon's floods began to walk the shores at night—not as spirits guided to Hades's gates, but as half-wraiths bound by seawater and will.

This was blasphemy. Souls belonged to him. No god had ever dared meddle with that flow.

And yet, Poseidon had.

When word of it reached him, Hades stood once again at the banks of Styx, staring down at the bloated reflection of his own face.

"Do you mean to challenge me, brother?" he whispered into the void.

The river swelled in answer, as though the sea itself pressed upward from beneath the world.

And Hades—for the first time in eons—laughed.

It was not mirth. It was not joy. It was the laugh of a god who saw storms on the horizon and understood that whether Olympus fell or the sea did, death would reap both.

But still, the choice loomed.

Would he harvest only, or would he ally?

Only time, and Poseidon's next move, would decide.