It's the competition of wills.
There seems to be only one of yourself when it's the moment of fight.
Now I understand all fighters are alone. And due to being alone he can do the ultimate that can't be done by the rest ones.
And many things would be redifined coz of the new state of life, including love, friendship, the meaning of life etc.
I know I'll be the winner at the end, not coz of anything else I have, but the Will.