Yes, I wonder what life will be like for those who haven't put their head in a tiger's mouth, so to speak. I mean, the other paths also need a severe power up.
To begin with, Butterfly's teachings on Cultivation or Dao should be completely unnecessary, since Tang Wei originally left the best method of Cultivation in the MC's head. The key word being "originally", since Nicky changed "left in your mind" to "left a few Qi Manuals around the world, search for them", which, in my honest opinion, was Nicky's way of explaining why the MC was acting like an imbecile who didn't even know how to cultivate even though he had the best manual in his head, also as a way of slowing down the MC's progress, because, in someone's mind, the MC "is progressing too fast" or the MC "is already too strong, needs to be nerfed". And this is completely ridiculous, because it isn't even in Tang Wei's nature to leave, beforehand, something for someone, let alone Qi Manuals in a world without Qi and in which he planned to kill everyone.