Who the hell did you think it was?
I thought it was the Sage; who's son's connected him to the Mazou so that he won't die.
What part of "Madara Uchiha rescued me" didn't you understand?
Uzumaki ( Rikūdo Sennin ) + Jūbi = Senju (Yang) and Uchiha ( Yin)
According to your formula; if we remove the Yin (uchiha) all we get is pure Yang (senju); but does the senju become a lot weaker considering his other half gets removed ? Do they equally potent each other ? Hm, Hm; We shall discuss upon this fragile situation.
Long live the Ihzumaki.