Utilizing both Yin Release and Yang Release at the same time grants access to Yin-Yang Release. It is said that Hagoromo was able to create something out of nothing using the Yin Release, and then breathe life into it using the Yang Release.
Here are all 9 Users of the Yin-Yang Release In Naruto
9. Asura Ōtsutsuki
Asura Ōtsutsuki was the younger son of Hagoromo Ōtsutsuki. He was entrusted with all of his father’s power. Asura was able to enter the Six Paths Sage Mode, which granted him 9 Truth Seeking balls. Furthermore, he was able to use all five basic natures, along with the Yin-Yang Release.
8. Toneri Ōtsutsuki
Toneri Ōtsutsuki was a Tenseigan wielder. He was also able to use the Tenseigan Chakra Mode. When in this mode, Toneri gained access to the Yin-Yang Release through the Truth Seeking balls.