Board Thread:Naruto Discussions/@comment-12509038-20140806073433/@comment-24519434-20140806092217

JOA20 wrote: Jashin Uchiha wrote: ItachiWasAHero wrote: Obito had his own Chakra and Hashirama's chakra, so of course Kakashi was able to get a make-shift EMS from that. He now has Perfect Susanoo and both Mangekyo Mastered and I will put this on the line right now, he can now turn them on and off and they now only drain him like they would drain a normal Uchiha. Kakashi is a mother****** BEAST. Except they had no drain on an Uchiha. The Sharingan requires chakra, so it does drain anyone, only that Uchiha are used to it and can turn it off.

Obito's sharingan never drained him, his eyes didn't even bleed after using his signature Kamui several times in succession.