Telesm of Interdiction

Among the most complex of known telesmata, the telesm of interdiction is also one of the most potentially powerful; however it is also extremely difficult to use effectively. It acts by projecting a potent warding field which prevents certain classes of entities from acting within them.
The telesm of interdiction was known to the Ordo Arcanorum of the Empire of Kataris; though due to the difficulty of their creation they were never used especially widely, broken inscriptions resembling them have been found at a number of Katari ruins including Skatha Visari and Kolis Etion. A few intact examples are said to survive in the lands that became the Eastern Katari Empire, now under the control of the Holy Republic of Vaalus and the Hegemony of Ecumanalus.
Whilst this telesm is designed to be created on a large scale, having a radius of effect proportional to the size of the telesm itself, it has been observed to be used in a different way by the magician Sanctity Falcoferri-Riddacci, who was able to imbue a crystalline focus with such a telesm and use it to spread the power of the telesm across an entire dreamscape. What techinques Sanctity may have drawn upon to create a telesm that acts in this way are unknown.

OOC Mechanics

Complexity: Extreme (DC 25)
Size: Location
Activation: 6th level spell slot

The area projects an invisible sphere of magical energy centred on itself, with a radius normally equal to twice that of the telesm itself. The sphere will penetrate through all solid matter other than orichalcum, which blocks it.
At the point that the telesm is made, an entity or group of entities must be specified to be warded against. This can be as narrow as one individual person, or as wide as "all beings that draw their power from the Four Hells" - however care must be taken to define it as specifically as possible, as this cannot be changed after the fact, and an ill-defined telesm may not function as intended.
Within the warded area, creatures affected by the telesm are subject to the following effects:

• The creature cannot percieve what is occuring within the area by any means.
• The creature cannot willingly enter the area by nonmagical means.
• If this creature attempts to enter the area by teleportation or interplanar travel, the effect automatically fails.
• Spells and supernatural powers originating or controlled by the creature can neither target, nor directly affect any other being within the area.
• The creature has disadvantage on all attack rolls against targets within the warded area.

It is notable that this telesm is sufficiently potent as to be able to affect entities which are normally immune to or substantially resistant to mortal magic of this kind, such as deities and the Paragons.

Related Discipline

Telesmancy