Tethrian Wall

*Disclaimer* This spell was originally built for a homebrew adventure and is based in a world of my creation, with it's own lore. It is not necessary to have this lore, and work with it as you would like. Enjoy! :)

Originally created by a powerful abjuration wizard by the name of Tethrik Kalantos; he was obsessed with possessing a way to assure his absolute safety and privacy, to protect his treasure and knowledge, that he had collected over the years. Tethrik devised over the coarse of three years, and finally managed to perfect the spell in the last 5 years of his life, before he was slain by his apprentice who betrayed him and took this spell, as well as Tethrik's vast wealth and magical knowledge. The spell is as follows:

The caster of the spell creates an invisible barrier, in the shape of a dome or sphere in an area centered on them; as big as 5 kilometers in diameter and 1 kilometer in height, or as small as 1 kilometer in diameter and 500 feet in height. This barrier is completely impassable, is immune to all damage, cannot be looked through by divination magic, and spells such as Scrying (Page 273 of PHB) or Clairvoyance (Page 222 of PHB). Spells such as Teleport (Page 281 of PHB), Dimension Door (Page 233 of PHB), and Misty Step (Page 260 of PHB) cannot penetrate the barrier. Incorporeal creatures also cannot pass through the barrier, but effects such as telepathy, or the spell Sending (Page 274 of PHB) can. Location cannot be discerned of a creature inside the area of the barrier if part of such a telepathy effect or other forms of magic. This barrier also, like mentioned before, is completely invisible. It can be seen by spells like See Invisibility (Page 274 of PHB) or by creatures with Truesight, and appears as a translucent, colored barrier (Color decided by the color of stained glass used in the ritual.), looking to be only a couple inches thick. The barrier temporarily becomes visible after physical contact with a creature or if targeted by a dispel magic spell, disappearing again after a minute. The barrier can only be dispelled by the creator of said barrier, or by a Wish spell (Page 288 of PHB).

Also in the casting of the spell, the caster must make 1 to 3 "Sigil Stone". The Sigil Stones cannot be destroyed by any means, and cannot be kept in the area of the barrier for more than 72 hours. If it is, it will teleport itself up to 1 kilometer away from the outermost edge of the barrier. The Sigil Stone item can be found under the homebrew section of dndbeyond for use.