In Mysterious Kaguya's terms, the fusion of Yin and Yang was the Kekkei Genkai of Yin-Yang Release. While it could indeed create all things, it was ultimately rather shallow in terms of realm.
The tenfold fusion of Yin, Yang, and the Five Elements was the Kekkei Mōra. If she absolutely had to give this one-and-only Kekkei Mōra a name, Mysterious Kaguya unimaginatively named it [Expansive Yin-Yang Release]. Wu Yu felt it could be called [Ultimate], or perhaps [Ultimate Release].
Having mastered the ultimate Ultimate Release, Mysterious Kaguya could transform Chakra into any form of matter with ease. Thus, she quickly separated out a strand of Chakra at Wu Yu's request and transformed it into a metal bracelet whose size could be adjusted.
Left Mysterious Tsunade found it novel. She took the bracelet into her palm and weighed it, finding it truly light as nothing.
Although Wu Yu had requested a metal that would not be easily damaged when he commissioned it from Mysterious Kaguya, it did not feel cold in his hand. The skin-friendly material felt comfortable beneath his fingertips, and its gray surface did not reflect light at all.
Left Mysterious Tsunade turned the bracelet over and found two black parallel lines circling its inner side.
Only those two thin lines were made of a material similar to the Black Rods embedded in the corpses of the Six Paths of Pain and in Nagato's own back.
Mysterious Kaguya's Chakra was still rather precious, and Wu Yu could not bear to have her make the entire bracelet out of Black Rods material. Its purpose was merely to facilitate Chakra transmission, so having some was enough; it was not as if he intended to nail Tobirama Senju to the ground and control that white-haired old ghost.
"Try it." Wu Yu reached