Living As the Villainess Queen (Web Novel KR) - Chapter 277.2

Though he received the skills necessary to teleport across worlds, the king who performed the summoning ritual attempted to trick him into wearing a slavery collar, this annoyed him so he kidnapped the princess and returned to Earth.

The story is about a boy entering high school, who answers a strange call from a public phone one night. The caller challenges him to a bet: She’ll remove the birthmark which he sees as the cause of so many problems, and he’ll have fifty days to win the heart of a girl he’d considered far beyond his reach. And with this, a very strange summer begins.

She was born into a powerful family of the nobility, a blue-blooded aristocrat as capable as any man. He rose from humble origins up the military ranks, an iron-blooded knight with high ambitions. A transaction for power severed her from her childhood sweetheart. A tardy encounter was the beginning of his and her vow to meet life and death under heaven, standing shoulder to shoulder.

Political intrigue, dynastic succession struggles. He trampled through it all in the toil of becoming emperor.

Old enmities became new disputes, concerning life and death of entire families. She entered once more into the palace, changing the entire political climate of their world.

Meeting once again, they had become strangers. The peach blossom were all fallen, no more than a golden age grown cold.

- Description from Novelupdates

Traveling to the wizarding world, Eli found that he was an Eternal.

Life is infinite, life is immortal.

“What? The talent is very poor, then I will meditate for ten years, centuries, and thousands of years, and I can always meet the promotion requirements.”

“This skill is hard? Oh, let me study it for decades to see if it’s really that hard?”

“Consuming life force, improving mental force, and this kind of good thing.”

“The enemy is here? Oh, let me find a place to hide for a thousand years, until his lifespan is exhausted and his mental power dissipates, and then I will come out again, free and endless void.”

…

This is the story of an immortal who lives in the wizarding world and then kills the endless world.

- Description from novelbuddy