The Weakest Substitute Makes the World's Strongest

[No system + growth + substitute messenger + campus] Luo Heng, a high school student, accidentally entered a strange space called the "Abyss" when he went out at 11 o'clock in the evening. I accidentally awakened my substitute in the abyss space, but... Why is my substitute so weak? There are monsters in the abyss, and the monsters crawl out from the bottom of the abyss and enter the real world. Here he met the "Abyss Crusade Team" composed of school clubs. On the surface it was a club activity, but at night it was a crusade against the Abyss warriors. Their goal was to completely remove the "Abyss" from the world. Everyone in the organization is a substitute, all because the "abyss" awakened their own substitutes Luo Heng: My weakest substitute is right, let me cut off the sins of the abyss. Come on, Thanatos! This is the story of an ordinary boy growing up to be the strongest in the world...