MTL - The Zombies Are Coming But I’m Laying Down At Home - Chapter 6 Sixth

A master assassin transmigrates into an interstellar era.

Left out during the elementary school picnic.

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- 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.