Most people don't choose reincarnation. Reincarnation finds their way to them. Perhaps they did something great in their life. Or maybe truck-sama wasn't looking where it was going. But without fail, those who reincarnate are destined for something great. A new life where everything changes for the better. But... Reincarnation isn't always the greatest thing. Sometimes you just draw the short end of the stick. Di Tou just happens to have drawn the shortest stick. Pulled out of his life randomly. Taken by a crazy old eccentric man not as a disciple, but as a body double?! And a janitor body double no less?! Grasping a system to find... It's a JANITOR SYSTEM!? Truly, how unlucky can one get?
Things like what they looked like, what dangers they posed, and how to deal with them were a bit beyond his grasp right now, other than the vague idea that using Void Qi on a large scale to affect the environment might have positive effects towards closing Realm Fractures, as they were a result of too much strain and complexity burdening the Heavens and causing it to burst.
By helping 'cleanse filth' and return the world to a more primal state, in theory his Void Qi could help reduce that burden, like ointment soothing a wound and causing it to deflate.
But that was just the basic concept based off what Mu Di Bai had told him the last time.