Despite the name, this relic isn't unique - or even a scroll, sometimes. It usually appears as a scroll, but more technologically inclined Superiors will provide this relic in book or even laptop form.

The relic is essentially a Talisman that can grant the Knowledge (Angels or Demons) skill. Soldiers of God get demon lore: Hellsworn get information on the habits of angels. Both sides prefer that their mortal servants not be exposed to too much information about the Other Side: providing these Talismans can prevent that, while still allowing humans to act effectively.

The Knowledge skill will normally provide basic Choir/Band information, the more powerful Words, helpful advice about various types of dissonance and how to recognize either Angelic or Helltongue - in short, the sort of thing that a celestial on either side would reasonably be expected to know. It's generally useless for fully-fledged angels or demons, for that reason, but relievers, imps and gremlins sometimes have a version of this Talisman. Generally, Scrolls of Zoroaster are more trustworthy, which is why most Hellsworn will do anything to get their hands on one (knowing your enemy is good. Knowing your master is better). Soldiers of God usually flip through captured Books of Crowley for laughs.

Sample Scroll/Book

Talisman/3 (Knowledge: Angels or Demons), grants skill 6pt

Convenience: Can be used in a completely hidden way 3pt

Vulnerable: Ethereal Artifact destroyed when corporeal form

destroyed -2pt

Fragility: Easy to destroy -2pt

Total Cost: 5pt