Board Thread:Naruto Discussions/@comment-24514198-20140604211103/@comment-24891350-20140611130159

Actionmanrandell wrote: its safe to assume that it used to much chakra to control the shinju either that or he did not fill like he needed to use kamui because he was all but immortal

The first part may be correct but the second is certainly incorrect as Obito himself stated that he could not use Kamui.