The Spirit Willow was not too dissimilar to Nibel's Spirit Tree, the main differences being purely aesthetic.
- The Core in which the Tree Spirit rests is much closer to the ground
- There are two main trunks which split at the core
- Though the Willow is not seen as she was in life, her temporarily revived ghostly form bears leaves that are appropriately more willow-like, dangling from the branches like wispy ribbons
- The Spirit Willow seems to be shorter than the Spirit Tree
The Spirit Willow is seen at the beginning of the game and later found at Willow's End, Ori's objective within it being the cleansing of the Decay that befell the Willow and is currently afflicting the rest of Niwen in the absence of the Light.
Ori and the Will of the Wisps Edit
Eventually, after Ori and Seir clear out the Decay beneath the old Willow, they make it to the top of the ridge to stand before it. It is here that Seir merges with and briefly revives the ancient tree, but it is only a ghostly specter of its former self. The Willow thanks Ori for healing what was lost. However, she says that her time is past and therefore can no longer care for the light. In order to replace her, Ori would have to embrace Seir, leave their old life behind, and become the new Spirit Tree of Niwen to save the lives of all. But just before their joining can take place, Shriek flies by, grabbing Seir to crush them in her talon before tossing them on the ground, leaving Ori to battle against her in a grueling final fight for the fate of Niwen alone.
During the battle, Shriek flies down into the unseen hollows in the earth left by the Spirit Willow's decayed roots. This causes an earthquake that rips beneath Ori as well as the rest of the Weeping Ridge which collapses, taking the remains of the Willow with it in the background. Ori defeats Shriek, but is wounded. As they limp towards Seir, they reflect on the memories they had in their life.
As soon as they reach Seir, Ori takes out Kuro’s Feather and lets it blow away. “It is time, Ori,” Seir tells them. Ori then holds Seir and light spreads from them, Illuminating Niwen. The light reaches Ku's resting place and restores her health and her deformed wing.
Ori is reborn as a sprout, growing from where the Spirit Willow used to stand, and gradually grows into the next Spirit Tree, replacing the Willow. A leaf is blown away from the tree, indicating the start of another generation of Spirit Guardians, replacing those of the Willow as decreed by the Will of the Wisps.