While Others Cultivate, I Use My Multiverse System - Chapter 144: Skirmish

Going for a swim, she ends up in an ancient wild Beast World and ends up being brought home by a handsome wolf.
She wants to stick to the handsome wolf, stock some salt, farm some land, look at some handsome men and grow old like that, but the handsome wolf pounces on her every day.
What? He wants her to have babies?
NO~ NO~ NO~ There is no happy ending to interspecies marriages, hurry and let go of me handsome wolf~

- Description from Novelupdates

Riku Barusak is a hard-working child. Despite possessing an innate superior physical strength and having withstood harsh training she fails to unlock her talent as a spiritualist. The failure results in her being thrown away by her family.

Abandoned, the only ones that extended a hand to her were the demons, the greatest enemies of the human race. Serving under them as a soldier she becomes a weapon of human slaughter, a fiend that should never have existed.

A master assassin transmigrates into an interstellar era.

Other players were responsible for competing in the e-sports arena, while he was responsible for stringing up and beating up the other players.

His sword was hidden during the peak of day, and he was a gentleman who arrived in a flash of light;
As a vanguard of the eternal night, he was the variable between life and death in the world.

“As you know, the Star League’s difficulty levels are arranged in this way:
Paradise < Simple < Normal < Difficult < Nightmare < Hell < [Tyron Odin]”

- Description from Novelupdates