I Am The Swarm - Chapter 803: Cooperation

The protagonist is an accidental time traveler - he didn't wait, didn't guess, only dreamed, but ended up in history, which he didn't pay much attention to. He was just lucky with his lineage.Ryo is a new member of the Nara clan, from the Uzumaki lineage on his father's side, and it so happened that he was born not at the beginning of the known plot, but more than three decades and two world wars later. Now he has to figure out how to get out of this situation however he can.

Reborn as Red Army Misha!

- Description from novelbuddy

Years ago when she was only a young girl, Rose ran away with her two friends Alexander and Mathias, just when they were about to be branded as slaves and sold to work in a brothel. Misfortunate fell on the group as Mathias became stuck and to save them, Rose sacrificed herself to distract the brothel owner’s son Graham who hunted them.Rose made her friends promise that in exchange for her sacrifice, they would return to free her. As the years passed and Rose reunited with her friends, she learned that all promises would not be kept.Stuck in a brothel with a man who wishes to turn her into his woman, Rose starts an unexpected relationship with Zayne Hamilton, a general of another kingdom. Zayne offers to buy her from Graham and opens the way for her sacrifice to not be forgotten.

This legend tells the tale of the protagonist, Kuroki summoned to protect the demon king from the hero.

Kuroki, unbeknownst to him, suddenly came to another world. He was summoned by the demon king, Modes. The territory which the demon king overrules was in the midst of being destroyed because of the hero. He had no choice but to bow before Kuroki.

“Please save us, Savior Dono!”

Kuroki nodded, deciding to save the demon king due to an unexpected turn of event.