Strongest Survival by Otome Game’s Heroine (LN) - Vol 5 Chapter 4: Academy’s Lesson

Mason was a mercenary, until the day he died on a mission after being betrayed by his unit.

This is an extremely difficult game, if you don’t have enough skills, don’t even think about going out!

- Description from Novelupdates

Pain, Pain, Go Away is a novel by Sugaru Miaki, also known as Fafoo, author of Starting Over and Three Days of Happiness. Unlike Miaki’s previous two books, Pain, Pain, Go Away is not a rewrite of any story posted to 2ch, but an entirely original one.

The plot involves a young man who becomes a killer (by accident) – but his victim has the power of “postponement,” temporarily delaying her death.

Upon traversing through time, Divine Doctor Qi Yu became a foolish Princess, the kind doomed to be entombed alongside her husband. Fortunately, her medical skills were exceptional. With a unique secret technique, she fished a certain Prince out of his coffin and performed a spectacle of raising the “dead.”Everyone said that after dying once, the Qi Family's useless Second Miss seemed to have transformed into someone else. Not only did she punch pure lotuses and kick duplicitous teas, but she also possessed the Resurrection Technique and mastered all sorts of martial arts, turning the entire capital city upside down.All the civil and military officials of the court begged the Prince to divorce his wife, yet the Prince, with an expressionless face, retorted, “The one spoiled by this Prince, if you can't stand it, just suck it up.”