Dreams collected from targets. Powerful creatures often harvest them from victims, Faeries of different sorts steal them from visitors to the Faeywild or Aelfpaths. Users of magic often harvest them in many ways in order to gain access to secrets or just to preserve a more tangible image than something mental which cannot be shared so clearly verbally. There are multiple ways of creating a Memory or Dream Bag (as it is most commonly known as).
d20 [specific] Requirements: Attunement ( Essence).
Can cast a Dream (Minor Illusion) with either audial, visual, up to 20m away. If the wielder (controller) is the same as the creator of the bag, then the illusion can incorporate both audio and visual at the same time – otherwise only visual. Generally, these bags consist of Dreams and Memories (a pre-set Minor Illusion; visual only by default). The Dreams cannot move beyond 3m from where it is cast, and Memories cannot move beyond 10m from where it is cast.
Assume there will be 3+d6 of each when found. After they are used, they are gone forever from the bag.