Lmao. The sage wonders why he failed as a parent. He favored the younger son and his ideals while making it obvious in front of the elder. Then, when the elder gets butthurt and throws a fit, he stays out of the fight and says nothing to ease the conflict. He watched years of their reincarnates fighting and never steps in. Then, when he finally does, he gives both brothers power while knowing that the elder reincarnate wishes to slaughter the other with the power he is receiving. And he gives Sasuke that power at the same time he gives it to Naruto, with him standing right there. Lol Hagoromo assisted Sasuke in his assassination attempt.
When he sees things going south, he decides that he has to leave and put all his hope in Naruto, when he did that for years beforehand and it never worked. He doesn't bother to take Sasuke's power back to stop the fight, even though he has the capability to do so.
Kishimoto ruined the sage's character tbh. Not that he had much character to begin with. It was just mystique that came with Madara's version of the story. Then, we get all this retcon from BZ and how Madara's telling was bs, then we see the Sage acting stupid. Kinda funny and sad at the same time.