A black oak branch, the length of a palm, was placed on the desk.
The last Sanity Value test involved a leaf; this time, it was replaced with a branch.
Lu Li faintly guessed the form of the Evil Spirit, "Is this a part of the Evil Spirit that can materialize the Sanity Value?"
An indescribably obscure aura emitted from the branch, and its appearance was somewhat familiar to Lu Li.
Hades seemed to have one too, but the aura on it was nearly depleted. Hades merely used the branch as an ordinary Homogeneous Item: to gnaw on.
"Yes, it's called the Soul Tree. The ritual involves absorbing the words of those around it and unveiling their mental veils. However, human minds are too fragile to bear its aura, often going mad from speaking around its true form. Until the first generation of Demon Slayer, Isaac Einstein, began research to decipher the Evil Spirits and used the branches and leaves of the Soul Tree for tests, eventually finding a way to localize Sanity Value."