Naruto: Starting with the Substitution Technique

"You have too little chakra." "You have no talent." "You are the most chuunin in your life." He had heard these words for twelve years. He didn't argue. He just folded each sentence and put it in his pocket. Then he returned to the toilet cubicle and continued practicing the stunt technique. Practice until your chakra consumption is only one-tenth of others. You don't need to form seals to master the Substitution Technique. He practiced until he marked thousands of White Zetsu in the corner of the Fourth Ninja War. No one knows who he is. But in the last line of the file, he wrote something to himself: "Using the stupidest method to get to the farthest place."