Board Thread:Naruto Discussions/@comment-142748-20150403221647/@comment-5936871-20150403222147

I believe it can only be achieved with EMS or in Kakashi's case, Six Paths Chakra. Cause with only the MS the user's chakra and life-force is consumed way to quickly manifest the susanoo to it's fullest extent. However, with EMS the negative drawbacks no longer exist rather then it eating up their chakra, although not as quickly, and therefore they can maintain it without dealing with so much pain and can bring out it's full power.