Reflectional Realms

Reflectional realms, also commonly known as Realms of Demons, are tiny pocket dimensions that come into existence attached to magical artefacts. 

Creation

Little is concretely known as to how these realms come to exist. Most agree that they are fuelled by magic or blood and attach to items. Some say that a sin is committed with the item, and the realms come to exist. These tend to co-occur with stories of Demons.

The Realm or Dimension

Visually, the dimensions are usually barren at first and develop the more magic or life-giving force is pushed into them. The rules of the real world are distorted there, but grow more concretely as the realm grows stronger.  The item to which the reflectional realm is bound will also appear somewhere in the dimension, functioning as a portal between the worlds. These portals often work according to their own logic. 

Creatures

The creatures beyond are usually monstrous, half-formed, and reflect the power and action with which the realm was created with. Some observed creatures are beings made entirely of blood, or glasswork monsters.
The creatures often pass through the portal connecting the real world with their realm, especially as the realm grows in strength. Some theorize these portals could be permanent, but none have yet to be documented. The creatures passing through can be killed in the real world. 
A controversial theory is the idea of a "First Being" in these realms - the first thing that the magic or blood had created. The First is then thought to be come akin to a god, able to harness the energies of the reflectional realm and control the creatures within.
See: Demons.

Destruction

The realm itself cannot be destroyed. When the item they are attached to is destroyed, passage between the realms becomes impossible, and the realm is cut off from the magic or blood that was feeding it. The dimension is theorised to shrivel and die.
This makes reflectional realms quite easy to deal with. Identifying them versus regular enchantments becomes the more difficult issue. 

Documented Examples

• The Mirror of Blood: A standing Cosmalite mirror created by members of The Aviary on the orders of Ardeth of Argo. The mirror was enchanted with the blood of the magical to reveal innate magic in those who stood in its reflection. Ardeth's ambition corrupted the mirror and formed a reflectional realm of blood, lead by a blood demon. The mirror was destroyed by Juyliette, Renard Cavendish and Alium Figura in the 'The Forge of Batu' by using the absorbed power of a Wellspring to overcome the cosmalite's indestructible qualities.
• The Glass Necklace: According to Head Curator Parchie of the Frontiersmen, she once helped destroy a glass pendant that had a Lady's reflectional realm attached to it. This process was relatively simple once Parchie understood what it was.  

Type

Metaphysical, Astral