Responses
Learning and getting used to something is harder than learning something new in the range of things you've already learnt, that's why I think it was easier for him to learn all the new techniques
While this is true I still think that it happened too fast, I would have liked to have a bit more of a meaningful build-up especially since the team leader recognised that it was amazing to do it first try, but I understand where you are coming from and maybe it is what the author thought as well
Honestly the art doesn't bother me that much but what is going with his sudden power up out of nowhere ? I feel like he learned all of the recent techniques too easily compared to how long it took him to understand traces