So let's talk about the different types of MC power growth and the pros and cons of the effect it probably should have on a character. First lets talk about cultivation; cultivation is all about sitting in a room all alone for hours to months. Some novels make the characters do this from the age of 4-6. Lets think about the effect being away from others just sitting in a room would affect a developing mind. I can think of a few outcomes: the character becomes quieter not knowing how to interact well with others, or they go somewhat insane.
Now lets talk about systems. Having everything given to you( power, money, talent) a and all that would go to someone's head. It would make them arrogant and selfish, and maybe they won't have a good grasp of their own powers due to it literally just being handed to them.
Lets talk about the training growth. You can think of almost any personality trait and apply it here.
If I missed anything please tell me
Lets talk about MC power growth
I do like the cultivation Road, especially if it involves understanding of the universe, it gives a good excuse to make your character talk less nonsense and make him wiser than his age
TinyRustyPanda
First, cultivation : Basically, the only moment you really "see" the MC meditating behind closed doors, it is only because he was too powerful for his environment. Let's face it, 99% of the authors use the 4weeks/6month/10 years/1 century or training to powerup all the other party to match the MC, so he can be insulted and slaughter the 18 families of his past and future enemies.
System : well, I did make a novel using that. So, no comment besides the fact that it is a pure nightmare concerning levels, experiences, stats. It is a complete mess of numbers and things, so pat on the back for everyone that rarely messed up those.
As for training growth, I don't understand what you mean.
Training growth, as in the discipline of the individual in following up with a rigorous training regimen? Perhaps the growth should depend on how much experience the MC has and how Knowledgeable they are in martial arts, bodybuilding, etc. Well depending on what they're training.
TinyRustyPanda This reminds me of a panel comic I saw where it shows the difference between western and eastern superheroes and how they got their powers:
cheezburger.com/7621782272/the-difference-between-japanese-and-american-superheroes
Eastern mindsets are all about gradual growth and training to overcome one's limits; whereas Western ideologies are all about immediate gratification and going from Zero-To-Hero as fast as possible.