Therefore, following the Kirigakure incident where he suffered a heavy blow from Uchiha Chi, and after prolonged and earnest persuasion by Black Zetsu, Obito finally realized that he had to take action to reverse the situation.
Although he knew full well that a skyrocketing of Nagato's power could very well lead to a loss of control, Black Zetsu's persuasion made him understand that of two evils, one must choose the lesser.
Moreover, Obito firmly believed that with the trump card in his hands—the mysterious Cursed Seal left by Uchiha Madara upon Nagato's heart, coupled with the pair of terrifying Kamui Mangekyou Sharingan he currently possessed—he would remain invincible from the start, entirely capable of keeping Nagato firmly within his grasp.
Chapter 401