TheTwoTwo
Think about it. If you have limitless potential that literally means your potential has no bounds. Put this into math. Let's say Toph has the potential to be a grandmaster by the time she dies which is 100(random estimate). Then, Mc with limitless potential has to surpass that alot earlier (like in 1 year) since his potential is limitless. When you have limitless potential it means you advance faster and steadier than everyone because your power peak(no peak) is at a level far away from everyone else's. So, for the Mc being a grandmaster is nothing it's an easy or almost trivial goal to reach cause it's not even scraping the tip of his potential. So he should not be following behind Toph he should be mastering everything easily especially in combat and furthering it and helping her. He should be able to pick up everything with one or two tries. He should be able to master things extremely fast and also create things unique to him alone since not everyone has limitless potential and super stamina. Yes, he has to train hard, however, his traning speed should be unrivaled and that's the truth and this truth is undisputable. One reasson that proves his training speed should be unrivaled and also makes it undisputable is time. Someone with a potential that is limitless can't take several years to achieve what other did in 1 year or several years they have to achieve it sevral times earlier. Also as he grows up it does not slow down but it speeds up. So, whatever Toph can do from birth to now, In a month or two at most he should be able to master and improve it. The novel should not be about Toph learning everything then passing it down to MC, because he is more than capable of learning it by himself. Also, earth bending can be enhanced in so many ways by MC without Toph no need to wait like how he is waiting with her right now for metal bending. From earth bending he can go on to stone, mud, metal, magma, meteorite, diamond, sand, atoms and particles and many other forms of bending branching of from earth. MC has so much room for growth. Really don't want MC to see Toph as some kind of superior or teacher when she basically still in the basics looking at what earth bending can do as a whole.
He should still train his physique. Later on when he has a deeper depth into earth bending he can use grivity to further his physique trianing. Should not be wasting his personsl time(it's a dangerous world in times of war) . Authour I am honestly just giving my critique and I beleive your making the MC to dependent on Toph. Depending in the sense that he is not doing anything outisde of Toph. Not traning abilities, not exercising, not even believing he can have fun without her or by doing things independently. Which is unattractive(not having your own thing, hobbies or ability you enjoy or is good at) and it's also broing. When I say broing I mean it just seems like everytime time he alone he just gonna read till he with toph again then the story continues. Hope you take this into consideration. There is no other novel like this on webnovel and this has so much potential and can go so far. Probably why I commenting so much (apologize if I went overboard, however it's really good so far and really want to help).