Bride of Sathla

5th-level abjuration (formula, ritual)

Casting Time: 20 hours (5 phases of 4 hours when cast as a formula)

Range: Touch

Components: V, S, M (incense and oils worth 1,000 gp, which the spell consumes; body of a ritually drowned humanoid), D (body cut into seven pieces and buried in a heptagram surrounding the area)

Formula Ability Checks: Intelligence (Nature) or Wisdom (Yog-Sothothery) DC 20 (diagram), Intelligence (Arcana) or Wisdom (Yog-Sothothery) DC 20, Intelligence (Arcana) or Wisdom (Yog-Sothothery) DC 20

Formula Backlash: One level of exhaustion and 5d4 psychic damage

Formula Failure: Magically frightened for 10 days and another level of exhaustion

Duration: 10 years

The Tcho-Tcho use this ritual—which prevents the entry of extraplanar creatures—to protect their villages. The corpse’s liver is removed, dried, and preserved as part of casting the spell. When the spell is complete, you touch a point and infuse the area around it with unearthly power. You choose the radius affected, up to 800 feet. The spell fails if this radius includes another bride of Sathla spell or hallow spell.

Likewise, a hallow spell fails if it includes this spell’s area.

Upon casting the spell, choose one or more of the following types: aberrations, celestials, elementals, fey, fiends, and/or undead. While the dried liver is within the area and the body parts remain buried, creatures of the chosen types can’t enter the area. Likewise, they can’t attack, charm, frighten, or possess creatures within.

Creatures that enter have any ongoing attack, charmed condition, frightened condition, or possession by such creatures suppressed for as long as they remain in the area. The duration of such effects continue to elapse while the creature is within the area. If a possession effect ends while the creature is inside, the possessing entity is driven out of the area instantly. Upon first interacting with this spell, a creature makes a Charisma saving throw. On a success, it becomes immune to that casting of this spell.

On a failure, it can’t try to enter again for 30 days.