Shinwa Densetsu no Eiyuu no Isekaitan - Volume 1, Chapter 3 – Awakening Part 6

Jinhyuk, a gaming Nutuber, was the only person who saw the ending of the game [Tower of Trials].

However, when the game’s popularity declined, it became difficult for him to continue making a living as a gaming Nutuber.

Since he already saw the ending of the game, he was about to quit playing. But that day, [Tower of Trials] became reality, and Jinhyuk, who knew about every single thing in the game, took over everything faster than anyone possibly could! “I’ll show you what a true pro is like.”

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.