Sigils

An idea to incorporate into the game:

There are three types of Sigils each for the express purpose of summoning, binding or banishing. The sigil is used to activate a filactarion containing soul components of its creator. There exists a handbook for creating the sigils. In effect this could form the skeleton of a "rod of many parts" quest: find the secret name, find the filactarion, find the sigil making handbook, make the sigil and summon the ancient queen.

[the more I think about it the more vanilla this feels. Open to suggestions.]