Unravelling the key to using the Creation Rebirth!!
Creation Rebirth, the ultimate medical technique. However, using this technique requires such an enormous amount of chakra, that it is beyond any shinobi to mould it in an instant. Tsunade, using the chakra stock kept in the seal on her forehead, has cleared this prerequisite. With Yin Seal: Release, the seal is released, becoming the source for the body regeneration technique.
The moment it is unsealed, a pattern appears on the forehead.
Releasing the seal is the greatest danger signal.
As far as I can tell there is no Strength of a Hundred Seal in the databooks, but there is Ninja Art Creation Rebirth — Strength of a Hundred Technique, but this doesn't mention chakra control at all. So the page for strength of a hundred seal is using the wrong referencing and has nothing to back up what is stated. Can someone please tell me where I can find the correct reference so I can check it please.
I think it was explained that the user stores its chakra consistently into the seal, even when they are fighting or doing other challenging tasks. So it obviously does require a crazy level of chakra control. Sakura stored her chakra for 3 years before releasing her seal in the war.
As it being the highest level of medical ninjutsu, you do have Naruto's yin-yang release, which can stop the dying effects of the 8 gates and can create human parts from nothing, but this goes way beyond medical ninjutsu and doesn't really classify as such. Other things like Hashirama's healing or nine-tails chakra also don't quite classify as medical ninjutsu, despite being on similar level as Strength of a Hundred Seal.
But it's not stated to be the pinnacle of chakra control, just very delicate or precise chakra. Also I think making them strong is side effect as doing the jutsu improves your control since you still use chakra when charging it so when your not doing that you control gets boosted.