Originally Posted by DRAGONBPY
I based my theory from this chapter as the sage got his power from Jubi and Jubi had both these powers.
i mean of course their powers came from the Juubi....though the story has already been told how the Uchiha and Senju came to be...The origin of their powers obviously comes from their father being the Jink of the Juubi.
Just as this chapter proved that he was born with the chakra. The tree wanted the chakra back and turmoil continued. The Sage as noted being the savior and using his powerful seal subdued the Juubi and placed him via seal within him. As he got older he realized how much of a toll the Juubi's chakra was doing to his body. He then sealed the body of the Juubi inside the moon and split the Bijuu into 9.
Edit: Is it just me or did Darth Vader destroy the moon partially???