This Seeking Tech guide will show you how to unlock The Owl’s Talon trophy in Ghost of Yotei.
For the first step, make sure you compete the The Way of the Kusarigama quest to unlock the Kusarigama weapon.
Afterwards, you need to unlock the Letal Talons ability from the Kusarigama skill tree by bowing at Altars of Reflection.
Once you get all of that done, you should unlock the ability to use Kusarigama as a stealth kill. Refer to the video below to see how to use the attack: