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?
If Di Tou was an ice cream machine, at the Nascent Soul Stage he would only have the 'vanilla' flavor. At the Resonance Stage, he was then a machine with both 'vanilla' and 'chocolate.' As for the Void Returning Stage, even if the ice cream machine could still only pump out the same amount of ice cream, there were now dozens more flavors, ranging from 'chocolate' to 'strawberry!' F*ck, he could even pull out sprinkles and toppings if that was what you wanted. Not to mention that he could combine them to create all sorts of new and wonderful effects.
And yet, Di Tou only knew how to pump out 'vanilla'. With such capability, although Di Tou was still using 'all of his strength', it was clear he was lacking in many areas. Even if he practiced some and learned about 'chocolate' or any other flavor, at most, he could pump them out individually like he had once pumped out 'vanilla.'