"Tatsu used to climb the mountains high atop Sorrow Pass... When her brother's torch faded, she fell into the mists, where she lost her path."
- Sein to Ori, after discovering the Ancestral Tree of Atsu's sister.
Atsu's Torch is a shining globe of illumination intended to light the Shrouded Lantern. According to Sein, Atsu's Torch faded and became lost in the Misty Woods at some point before the present time, causing the Shrouded Lantern to radiate mist from its stem.
Retrieving Atsu's Torch and using it to relight the Shrouded Lantern is essential to the continuation of Ori and the Blind Forest, since this will grant Ori access to the Forlorn Ruins via the Gumon Seal.
Atsu's Torch is revealed fairly early on in the Misty Woods, but it can't be recovered until later. As Ori begins their journey through the area, Sein spots the Torch and suggests that bringing it to the Shrouded Lantern might clear the haze.
When Ori is able to collect the Torch, they must carry it back to the Shrouded Lantern. Upon arriving there and using the Torch to lift the mist, Ori will be presented with the Gumon Seal, allowing them to progress to the next area.
- Atsu's Torch is named after a Spirit Guardian of the same name.
- Atsu and Tatsu are related. Sein confirms this when Ori discovers Tatsu's Ancestral Tree.
- It is never actually clarified whether or not Atsu's Torch was lost before or after Kuro blinded Nibel. Currently, both theories are possible.
- Atsu's Torch, Light Vessel, and the Light from the Spirit Tree (Definitive Edition) are very similar in several aspects. All are required to progress through certain areas, are heavy but can be carried by Ori, and they all shine with elemental light.
- Atsu itself derives from the Japanese language, and means either "Warm", "Sincere", or "Honest".