how about the way the ninja\'s do it that isn\'t inside a game yet so it would be kinda original ( it is in movies and comics )
you have 8 gate\'s of chakra
initial
heal
life
harm
limit
view
wonder
death
initial and heal are able for normal people to achieve, if you try to go to limit the body of a normal human would perish and the human will die.
if you are able to open all the gates you are extremely powerfull but it would also have a bad side to your body, your muscles would snap and you wouldn\'t be able to move, on the other hand you are so focussed that you won\'t notice this until you are at the first gate again.
to work this out you can use a system that the higher the gate you get to the stronger you will be but your health will also go down.
sort of the same system as the state of mind only then the taijutsu way