Board Thread:Naruto Discussions/@comment-3568954-20140803003603/@comment-5407586-20140803054553

Only Uchiha clan members can achieve EMS, since it needs two different Mangekyo to overlap with each other. Senju cells may help slowing down the process, but only a true Sharingan wielder can bring out the full potential of the dojutsu, especially if it's two eyes of the same pair.