From the Start, I Get a Wife, and Become a Heavenly Emperor Through Yearlong Simulations

Gu Ziming transmigrates to a fantasy world and becomes an odd-job disciple at the Tai Xuan Holy Land. Useless as he is, his odd-job fiancée looks down on him and cheats on him. Fortunately, he binds himself to a lie-flat System. Lie flat every day and get a one-year cultivation experience pack. As long as he simulates cultivation, he can grow stronger. Just as Gu Ziming is about to take revenge, he encounters the Holy Land's saintess, who has been struck by a deadly poison. Without a word, the saintess takes Gu Ziming as her cultivation cauldron. The two make a pact to meet again in a hundred years.