Ghost of Tsushima: Ghost Mask
Ghost of Tsushima's Ghost Mask is one of the masks available for Jin in the game. You can acquire it by completing the quest From the Darkness.
Among all the masks available in the game, this has the most impact on the story of the game, as it involves one major character in its creation. This is also the mask shown in most trailers of the game.
You can select the mask you want to wear from the Outfit menu.
Visit our Ghost of Tsushima 100% Walkthrough to get more details.