Once the update patch has been applied, the Ryu Hayabusa skin can be obtained from the Shrine Boons menu. This addition is to celebrate the recently revealed Ninja Gaiden Master Collection.

As mentioned, all you need to do is download Nioh 2 update 1.26/Nioh 2 update 1.026.00 for PS4 and PS5, respectively, and you can grab a the Ryu Hayabusa skin via the Boons tab from any Shrine menu.