Mercenary's War - Chapter 16 - The Importance of Mental Quality

Haruma Kazuki is a cursed (or maybe just deeply unfortunate) high school student whose lewd, panicked, or absurd thoughts literally manifest in reality — especially when he tries not to think about them. The more he denies or avoids feelings, the more chaotic and trope-heavy the consequences.

When a cold and crafty girl travels into the body of a foolish, man-crazy, young female aristocrat, what will happen?

Our MC dies from an accidental electrocution and ends up inhabiting the body of a young prince in another world, his new profession being the Necromancer he chose in the game he was playing before his untimely demise. However, things are not what they seem – including his own Necromancy skills!

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