Board Thread:Theories and Speculation/@comment-28939725-20170414154636/@comment-25122992-20170414163356

Actually, it does. The databook description mentions that the user's death is inevitable, and even Obito himself said it to Madara when they and Ten-Tails fought against Shinobi Alliance. Obito didn't die immediately because of the particular reason that was mentioned as well - Black Zetsu was prolonging his life back then as long as it was clinging to his body. When BZ left his body, Naruto used his Yang powers to prolong Obito's life once more, but both of them still perfectly realised that Obito cannot be saved and would die later anyway. You should read the technique's article, seriously.