In the anime Naruto, the Great Snake Maru is called the first scientist in the ninja world by fans, and the Great Snake Maru also relies on his own scientific research to make himself have an immortal body, and although he has obtained the immortal body by learning the immortal rebirth, this forbidden art has another drawback, that is, he has to change his body every three years, which is the only drawback.

Therefore, every three years, the Great Snake Maru had to find a new person as a sacrifice to reincarnate himself, and the target of the Great Snake Maru was also placed on those ninjas who had the Blood Inheritance Limit, and among these people, the Great Snake Maru was the most optimistic person, one was Taketori Junmaru, who had a corpse bone vein, but in the end, because Junmaru was suffering from an incurable disease, the Great Snake Maru gave up on him.
The remaining two people were Uchiha Ferret and Uchiha Sasuke, and the great snake pill most wanted to get the bodies of these two people, but the great snake pill was also tortured by the two brothers, first of all, when he seized the body of Uchiha Ferret, he was killed by Uchiha Ferret, and then when he seized Sasuke's body, the great snake pill was directly killed by Uchiha Sasuke, which was not expected by the great snake maru.
During the Naka Ninja Exam stage, The Great Snake Maru inadvertently found Sasuke Uchiha and left his own spell mark power on Sasuke's body, and the Great Snake Maru was also sure that Sasuke would definitely go to find himself, indeed just like the Great Snake Maru thought, Sasuke did defect from Kiba Village and come to find himself, but at this time, the Great Snake Maru had reached its limit, and he could only find someone to reincarnate at will.
However, the Great Snake Maru obviously still has three years to go, he can directly lock up Sasuke, and then he only needs to wait for three years to seize Sasuke's body, but the Great Snake Maru did not do this, the Great Snake Maru not only taught Sasuke some ninjutsu, but also cultivated Sasuke with his heart, but some people will say, Big Snake Maru, is this his own life? Why train Sasuke?
First of all, Sasuke came to the Great Snake Maru for a simple purpose, that is, to give himself great power and to defeat Uchiha Mustela, if the Great Snake Maru did not cultivate Sasuke, Sasuke's temper would definitely leave the Great Snake Maru here, if the Great Snake Maru forcibly left Sasuke, Sasuke may even commit suicide, so the Great Snake Maru must be careful with Sasuke.
The second reason is related to the Great Snake Pill's immortal rebirth technique, first of all, the containers found by the Great Snake Pill are ninjas with blood inheritance limits, which shows that the Great Snake Pill can directly have the power of the container itself, and the better the foundation of the container, the stronger the strength, the Great Snake Pill can have stronger power, in other words, the stronger Sasuke's strength, the stronger the chances after the rebirth of the Great Snake Pill.
Of course, the third reason is that the Great Snake Maru did not expect that he would actually die at sasuke's hands, first of all, the Great Snake Maru was really too weak at that time, plus he had already weakened some of his strength by going to his hands, and then the forbidden art of immortal rebirth, when attacking Sasuke, he was directly killed by Sasuke, which was also the strength of the Uchiha clan who had the wheel eye.
In fact, it can only be said that the luck of the Great Snake Maru is bad, if Sasuke can come to the Great Snake Maru earlier, then Sasuke may directly become the container of the Great Snake Maru, but the fate is so ingenious, the Great Snake Maru lost the only chance to seize Sasuke's body, and this means that Uncle Snake will never have the opportunity to seize Sasuke's body again.
In your opinion, why did the Great Snake Maru want to take Sasuke's body, but still cultivate Sasuke?