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?
Overall, although Li Chang Hu felt like Di Tou's temper was rather agreeable for the most part over their last few days of interaction, he didn't want to cause trouble. In any case, he had finally managed to invite this expert over to visit the Academy and 'play around' for a few days under the pretext of helping give a lecture to a class of students. As long as Di Tou's abilities wasn't too bad outside of the specific domain he was good in, and he wasn't hiding any disastrous secrets, it shouldn't be too much trouble to get him a position at the Academy.
In the end, it had to be said that no matter what world you were in or the situation, having the capability to stand heads and heels above the masses would bring some privileges and ease of access. In this case, Di Tou's high cultivation gave him an easy way to enter the Academy that so many others desired but could never truly enter.