The Demon King Needs to Cure Love-Brain Syndrome

Before Eustace became the Demon King, he was a hopeless romantic.

A fisherman broke the ice and rescued him, then gave him a pair of unused gloves. Eustace fished day and night to earn money for the fisherman, until his hands became raw and ulcerated.

A prince sent him to school to learn and gave him a rose. Eustace fought wars across the south and north for the prince, until the prince's rose gardens and territories spread across the entire continent.

The legendary hero gave him a bowl of hot soup and saved him from a dragon. Eustace swore to follow the hero to the death, fighting the fearsome demons of the abyss for him.

But his passionate heart was never cherished. It was shattered again and again.

The fisherman sold him for a silver coin.

The prince laid a devil's curse upon him.

The hero pierced his heart with a blade.

The Demon King Eustace reforged his body and abandoned love, regarding everything in his past as a shameful history he could hardly bear to face.

A hundred years later, an accident sent the Demon King back in time, where he met his sixteen-year-old self.

His past self, a boy named Xavier, was happily fawning over the fisherman.

He tried and tried to hold back, then decided to kick this embarrassing fool away first.

-

Back in the past, Eustace had two things to do:

1. Cure his romantic obsession without changing the course of his life.

2. Find the time scroll, return to the future, and fulfill his duties as Demon King.

But things didn't go as planned. Eustace completed his mission ahead of schedule. Xavier also took a completely different path from his own, a bright and happy one.

Eustace closed his eyes, satisfied. The holy angel Xavier was born from the flames, the gears of fate shifted, and the future Demon King vanished from the world forever.

Across the city in the sky, the molten abyss, and the vast continent, the angel beat his wings and searched the whole world for his beloved.

But this time, he could never find him.

-

A curse of fate. Twins on opposite shores. Never to meet again.

The temple collapsed and the gods fell. Xavier sat amid the ruins of the mortal world, the one and only god obsessively and frantically pleading: "Don't you love the demon race most? Don't you love humanity most? Come back. I'll be good and do as you say. Come back, please..."

-

At some unknown time in some unknown year, the Demon King Eustace sneaked into the surface world to have tea. When he glanced over, he saw a pair of beautiful eyes.

Their irises were ice blue, but the pupils at their very center were crimson, like lava that never went out beneath the sea.

Eustace gazed at those eyes in confusion, and from that moment on, he could never look away.

-

"The gods cursed me, leaving me utterly alone, to wander the world by myself. The mortal world hates me, and no one loves me."

"But I have a beloved. My beloved is the moon reflected in water, a flower in a mirror, a phantom cast by the river of time, another branch in the fork of fate."

"If I exist, he exists. If I am eternal, so is he."

"He is the undying flame in my heart, the embodiment of all my ideals, and my most flawless love."

Content warnings:

Selfcest, with the protagonist both giving and receiving.

Happy ending, with success in both love and career!

The Demon King is the shou. He reforges his body, so it isn't the same body.

The gong lacks confidence early on and sees himself as a tool. He only wants to be useful. His feelings for other people aren't romantic, but dependent. The only person he loves is the shou!!!

Theme: Don't forget to love yourself.