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?
In fact, the last time Di Tou was at the Academy, he had already considered this aspect and done his best to try to get combat techniques and methods that were above his level, so that even if he were to grow swiftly, they wouldn't be outpaced by him. After all, the lesson of his most powerful methods becoming rather useless was rather jarring and had sunk deep into his heart. At the end of the day, he wasn't a battle hardened warrior, he didn't want to go in fists swinging! If he could have a gun, or even just a sharp spear, that was plenty better then his fists. Techniques were such a thing to him. A way to alleviate the risk, and a tool to help him control his strength.
The techniques he learned in that time were all above his level, or had room for growth. Even if they were most suitable for a Nascent Soul Stage expert, at the very least, they still had value in the Resonance Stage.