Naruto's Library of Heaven's Path.

After traversing the Naruto World, he obtained the Library of Heaven’s Path. The Library of Heaven’s Path allowed the main character to see through the strengths and weaknesses of anyone. It could even fuse all sorts of innate skills, escape techniques, and limits of the Blood Successor. Hence…

"Sasuke boy, this isn’t how you use Shurakan. You still have a lot to learn! Do you want me to help you evolve into a kaleidoscope?”

"Little Li, come, I’ll teach you an Eight Gates technique that won’t harm your body at all!”

"Kakashi, do you want to learn Shenwei and Susaneng? Come, become my disciple and I’ll teach you!”

"Eh, did Orochimaru invade the wooden leaf? Xiao Li, go, teach him to turn over a new leaf!”

"What is it? Pei En was here too? Was he here to invade Muye? Oh, no? So they came to beg me to teach them ninjutsu? Hehe, let them kneel outside for three days first.”