Devil_Hex
He became complacent. It was to be expected, he is a member of an important clan, the praise of being a jounin at his age was too much. He got carried away with it and lost. He is like Hiruzen mentioned in a chapter. Fujin has a conviction when it comes to training that no one else has. While many become complacent about becoming a fujin jounin he knows that they will only be cannon fodder in the war to come.