Gnosis

8 This sigil possesses some protection against the power of the Wyrm. Servants of the Wyrm revert to their true forms if the sigil activates in their presence. Some believe that this action alerts the Wyrm to the existence of the sigil, but in any event, the sigil combusts in a greenish fire immediately after use, and is incinerated completely.

To create a Wyrm scale, a Wyrm-spirit must be bound into the sigil.