Malignant Information

A requirement for the appearance of the Tatari. Shared common knowledge circulating throughout a closed community.
Develops by making use of things like anonymous accusations, improbable testimonies, and popular trends. It will take on various forms depending on the circumstances, but at its core is “nothing.” It is for this very reason that the Tatari itself is said to have no true identity.
The “Bad News” used by the Night of Wallachia and the “Terror News” used by Vampire Sion were both forms of this, materialized with magical energy. The creation and control of malignant copies is a particularly advanced application.

MB Act Cadenza PS2 Manual: Tsukihime Dictionary