Board Thread:Naruto Discussions/@comment-24373005-20140811055011/@comment-25294762-20140812065830

In honesty I think if you have a Sibling eyesight burns up faster then if you do not have a sibling. Cause you do not have anyone to replace your eyes with. But Kakashi did state that it was becoming harder for him to use Kamui when him and Minato were fighting Black Zetsu/Obito Body.