Theory| The Origins of the Moukuton
The Origins of Moukuton
Moukuton (roughly Wood Release) is a KKG, that is arguably the best Nature Release there is as it can passively absorb chakra, extend far lengths, and summon a variety of powerful beasts such as Moukuton Dragon or Shinsuusenju. However the origins of the Moukuton are sketchy to say the least. Why is it that only Hashirama possess it if it is a KKG? Why can't other people who could use Earth and Water Release use it? In this thread I'll be answering these questions,..!
Why is Wood Release considered KKG? No other Senju has shown to be able to produce Moukuton so why is it a Senju oriented thing? Simple due to another power that has been revealed to be possessed by Hashirama Senju; Sennin Mode. We've seen four people that have been able to use Sennin Mode: Naruto, Hashirama, Jiraiya and Kabuto. Arguably Kabuto's Sage Mode isn't perfect due to the blackening of his eyes and Jiraiya's is known to not be perfect. This leaves Naruto and Hashirama and what do they have in common?
They're both Senju related. Whether the Uzumaki are the clan that the Rikudo Sennin was a part of or not doesn't matter, we know that the Uzumaki and Senju are relatives. Since out of four people, only two which are Senju related were able to accomplish Perfect Sage Mode, this leads me to believe that only Senju's or Uzumaki's could perfect Sage Mode as it is part of the Body Energy phenomenon.
So this still doesn't explain why it is a KKG. Well since on Senju could perfect Sage Mode then it must be related to Mokuton. Wood Release has been noted to be a mixture of Earth and Water release but I don't believe that was it. Trees and wood are a natural phenomenon so how could mixing two create living being? You need Sage Mode or know how to balance Natural Energy to some extent.
When mixing absorbing natural energy while simultaneously using Earth and Water Release, it results in Mokuton - this is why Wood Dragon etc. absorb chakra as it is spirtual and physical energy mixed with natural energy, resulting in the absorbtion of chakra in itself.
To summarize all of this, Mokuton is a KKG because only Senju and Senju relatives could perfect Sennin Mode. The simultaneous use of Earth, Water and passive Natural Energy absorption ends up in Wood Release. Hope you enjoyed :D