Board Thread:Naruto Discussions/@comment-24855911-20140508215614/@comment-17623-20140509014513

Black Zetsu is an oddity, for everything. Yin-Kurama was sealed in him, but Obito was able to transfer it to Naruto, implying it was actually sealed in Obito, but at the same time the black substance alone was enough to carry the tailed beast and the Rinnegan to Madara.

Black Zetsu is weird.