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The Fission Technique is a highly advanced ninjutsu which allows Mū to literally split his own body into two identical — yet entirely independent — duplicates of himself.
Unlike clone techniques that only appear to be similar, the ability is instead a physical separation and so does not require hand seals to activate, making it faster in comparison as a result. This also means that even if one is incapacitated, the other remains completely unaffected and as neither can truly be regarded as the original, the duplicates cannot be dispelled like normal clones. Because Mū's chakra reserves are also halved, he is left unable to use more taxing techniques like his Dust Releasekekkei tōta.