MTL - Manga Guidebook - Chapter 140 sorry i'm late

A 29 year old civil employment exam student wakes up in a blank white room and meets a baby angel. This baby angel informs him that he died in his sleep due to heart disease like his father and grandfather. Remembering his mom and their last conversation he says that he will take on a series of life and death tests that the baby angel offers him. From this point on he must put his life on the line and fight in the stage called ‘Arena’. And Every time he clears a test he will gain abilities and weapons to increase his strength. All to clear the tests and get his life back. This is his story of his fights in the ‘Arena’.

A wonder falling down from heaven! A boy possessed by strange blood! Gods tremble! Demons flee! A boy from the land of Dong Zhou. A pink skull as his sworn friend until death. A story of a determined warrior struggling for power. A legend that shakes the galaxy and disturbs the worlds of god, demon and man.

- Description from Novelupdates

Upon meeting the girl who would become her adopted younger sister, the duke’s daughter Christina regained memories of her previous life. Through those memories, she learned that her new sister, Mishuli, was the heroine of a certain story. And though the story depicted a Christina who abused her sister, the real Christina turned into a siscon who spoiled Mishuli to no end.

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