Besides being comprised of the Yang Release nature transformation, the actual applications of this power aren't clearly understood. What was shown, however, is that it empowers the user's techniques with Six Paths Power, enabling them to harm the Ten-Tails' jinchūriki. It is possible that it augments the user's other abilities.
As noted by Black Zetsu, there is a special resonance between the Six Paths Yin and Yang powers, allowing the wielders to sense each other's presence. When the Yin and Yang powers are used together, they can transform their target into the core of Chibaku Tensei. When Naruto did so in conjunction with Sasuke Uchiha's Yin power, the mark on his right hand vanished, returning to Hagoromo's own right hand.