The Villainess Enjoys Her Seventh Life as a Free-Spirited Bride (hostage) in a Former Enemy Country - Chapter 12: About the maid’s ‘senpai’

After dying from betrayal, Thomas reincarnates as Jolthar Kaelzhar, the neglected son of a powerful clan, just after his brothers kill him. With Jolthar's memories and the blessing of Qalena, Thomas vows to rise from his lowly position and claim power in his new life.

When encountering demons, a young man with two horns on his head, red hair reaching his waist, and an extremely handsome appearance leads the demons to the front.

Youdou: Actually, I really don’t want to be a master of monsters. This profession is completely useless. My ideal is to become a magic stick…, bah, it’s to become a great onmyoji.

All the monsters: My lord, wake up, you are the leader of the monsters yourself!

- Description from novelbuddy

Asura, a noble in the kingdom of Silvara, spent his days quietly until his world ended. Betrayed by his beloved wife and then killed, he swore to get revenge on them in his late moments. Upon death, Asura somehow returned 20 years into the past. Prepared to get revenge on the woman who betrayed him.On his journey for revenge, he discovers true love, friendship, and a life-altering truth.A dark cult controls his fate like a game—even his beloved's betrayal was their work. He learns about his powers and strange bloodlines. Then, about this being his ninth and final rebirth! All to revive their god, using Asura as the perfect vessel.Vowing to destroy the cult's plot and protect his loved ones, Asura forges an alternative path.Becoming the Devouring Monarch

Three Days of Happiness is a novel by Sugaru Miaki, also known as Fafoo. It’s a rewritten version of the story originally posted to 2ch.

The premise of the story revolves around a shop where one can sell away the remaining years of their life, and the consequences of doing so.

“I Say A Little Prayer” is a short related story which was posted along with the novel’s release. It spoils some things about the main story, but nothing major.