Cultivating Immortality with My Sister in Uncle Jiu’s World

[The synopsis isn't doing this story justice, so read the main text.] Ye Qilang transmigrates into a world of zombies and gets bound to the strongest cultivation System from the start. As long as he slays demons and drives out evil, and delivers the dead to salvation, he can earn cultivation points, which can directly raise his cultivation level. With the System's help, Ye Qilang's cultivation advances by leaps and bounds, and he rises to the pinnacle of life. [The writing isn't great, so here's a feel-good power fantasy instead.]