The Undefeatable Swordsman

A brief description of the manhwa The Undefeatable Swordsman: 

Sometime in the future, a boy will be born with a special painting. This painting will grant the boy great power, but it will also make him crazy. He will have to hide this power from everyone, and live as an outcast, until he learns to control it.

When he does, he will be able to use this power to defeat all of his enemies. “‘I want to see it!’ said the boy. “‘I can’t show it to you now,’ I told him.