Shinji had not arranged for Haku to try learning Senjutsu on a whim. He had been considering it for a long time.
As his own strength had grown, so had his perspective and knowledge. His understanding of Chakra and Natural Energy had also become much deeper and more thorough!
In his view, successfully mastering Senjutsu required meeting several conditions.
First, one had to possess a vast amount of Chakra. This was a prerequisite for mastering Senjutsu. Only with enough Chakra could one harmonize with Natural Energy and successfully fuse the two to form the foundation of Senjutsu—Senjutsu Chakra!
Second, one needed a strong will.
Among the Shinobi World's Senjutsu users, such as the First, the Fourth Hokage, Jiraiya, and Kabuto Yakushi, every single one had an unshakable will.
Otherwise, even a genius like Jugo, who was naturally able to absorb Natural Energy, would often lose control and enter a berserk state due to a lack of willpower.
Third was the elusive talent for Senjutsu.
Over the years, only a handful of shinobi in the Shinobi World had mastered Senjutsu. The only explanation was that most people lacked the necessary talent.
Shinji had arranged for Haku to learn Senjutsu because he believed Haku met at least the first two requirements: Chakra reserves and willpower. As for the third, talent, Shinji figured that anyone who could master the Breathing Technique, awaken the Curse Mark, and enter the Clear World couldn't be lacking in talent.
Of course, there was definitely an element of gambling in Shinji's decision.
At this point, Shinji's enemies had changed. At first, he had faced enemies below Six Paths level, like Nagato, Obito, and Danzo. Now, he was up against powerful foes like the Overlord and Ōtsutsuki Isshiki, who were at least Six Paths level.
So he had to