Board Thread:Naruto Discussions/@comment-24531362-20140723084127/@comment-24022934-20140728125311

Kamui doesn't seem to be very hard to use, Kakashi had a hard time because he wasn't adjusted to its power, and he also had very low levels of chakra to begin with. But even he could just warp an explosion from Deidara the 4th time he tried, so it's not that hard. Obito is the the one who naturally manifested Kamui, it isn't odd that he can use it to its fullest extent.