The Simple Life of Killing Demons - Chapter 38Book 12:

Seong Eugene, a student at Gukcheon University, is recognized for his latent potential as a hunter but shows no signs of awakening by the age of 21.One day, his intense desire to awaken triggers his latent abilities, and he awakens with a new smartphone app.He invests five points to increase his physical attributes, specifically enlarging his penis to 16 cm. As he explores his abilities, he discovers he can conduct random draws for items and skills, acquiring several items and a complete recovery skill. His unique ability allows him to enter fictional worlds, and he decides to test this by entering an AV film he watched a week earlier, SV-7495.

A Deadly Secret, also translated as Requiem of Ling Sing and Secret of the Linked Cities, is a wuxia novel by Jin Yong (Louis Cha). It was first published in the magazine Southeast Asia Weekly (東南亞周刊) and the Hong Kong newspaper Ming Pao in 1963. Its original Chinese title was Su Xin Jian before Jin Yong changed it to Lian Cheng Jue. The story revolves around the adventures of the protagonist Di Yun, an ordinary young peasant, who is imprisoned after being framed. In his quest for vengeance, he accidentally acquires the Liancheng Swordplay manual (連城劍谱), an ancient artifact not only prized for the skills detailed inside, but also for containing a secret leading to a treasure.

Coincidentally, indoorsy-guy Zhang Yang went to the cultivation world, being the lowest level of zombie. By using a manual book named: “ Tai Yin Refining Figures”, Zhang Yang find his own way to success and leaves a “If a zombie knows how to use a manual, nobody can stop it “ legend in the world.

- Description from Novelupdates