Board Thread:Theories and Speculation/@comment-30355627-20170210181343/@comment-30168130-20170211043813

yup. obito had to use his own chakra (which already had sp chakra added to it), sakura's and naruto's, just to connect his own portal with all of hers. imagine sasuke by himself going back and fourth. (I know its probably easier for him than obito but still..)