The Two Lives Technique was a sage technique in which Sage Shima, Sage Fukasaku, and Jiraiya fused together, with the two sages standing on his shoulders.
This technique offered a great deal of flexibility. It allowed not only partial fusion and complete fusion, but even the forced fusion of certain living tissues. Under the coercive pressure of the three sages, the Rinnegan had fused with Jiraiya through sage chakra, allowing him to wield it freely for the time being.
This method of control was naturally far more reliable than a simple transplant, but the consumption also increased drastically.
Since Jiraiya had been able to cultivate Sage Mode, neither his chakra reserves nor his physical condition could have been poor.
He did not possess the physique of the Uzumaki Clan, nor did he have the adaptability of the Uchiha Clan. Reaching this point was already exceptionally difficult.
The Two Lives Technique was essentially a sage-version advanced form of the Combination Transformation Technique.
Jiraiya had gone to great lengths to figure out how to effectively use the Rinnegan. After learning of the connection between the Rinnegan, the Demonic Statue of the Outer Path, and the Ten-Tails, he knew that if they ever fell into a disadvantageous position, using the Rinnegan in his hand to fight had to be placed on the agenda. Otherwise, relying on the immature Naruto Uzumaki to turn the tide did not seem particularly safe.
As for another candidate Jiraiya believed might be able to make a difference, that person seemed to know even more unsettling information and was not very proactive about handling the current situation, clearly held back by too many concerns.
Those who knew the most inside information, including the Great Toad Sage, all remained tight-lipped. Jiraiya could not force them, but doing what needed to