MTL - Civilization: Beyond Two Worlds - Chapter 699 Duke Kant

“I am Yang Jian. By the time you read this, I've already been dead...”A strange parchment, an eye that peeks into the darkness. This is the memoir of a person who survived.

The genius cultivator Lin Xuanzhi didn’t let down the world in his past life, yet he only betrayed a single Yan Tianhen.

It was only when he had been backstabbed and killed by his closest friends, teacher and fellow disciples that he knew what kind of unforgivable crimes he had committed.

After he gained the huge opportunity for rebirth, the Lin Xuanzhi who had climbed back up from hell swore to cherish the person that he had betrayed in his past life.

- Description from novelupdates

In a world where magic intertwines with reality, a dying human girl named Elara awakens to find herself in a foreign land. The air smells of ancient forests, and the sky is painted with hues she’s never seen before. Before her stands the enigmatic Demon Queen, Seraphina, her eyes as cold as the ice that encases her throne.Seraphina proposes a desperate bargain: a contractual marriage between them. In exchange for Elara’s hand, Seraphina promises to save the crumbling human kingdom from impending doom. Elara, with nothing left to lose, accepts, thrust into a web of intrigue, danger, and forbidden emotions.As they embark on their perilous adventure, Elara discovers that Seraphina’s icy demeanor hides a tragic past. The Demon Queen’s power is unmatched, her wrath swift and merciless. Yet, beneath the frost, Elara glimpses vulnerability—a longing for connection that defies her ruthless reputation.

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.