Call Father Yog-Sothoth

9th-level conjuration (formula)

Casting Time: 10 hours (5 phases of 2 hours when cast as a formula)

Range: 60 feet

Components: V, S, M (a complete copy of the Necronomicon and a gate spell connected to the nameless gulf between planes of existence, which has no effect other than serving as this spell’s component), L (an elevated, ruined or desecrated temple of any deity), T (beginning at sunset), SC (0 to 8, which must be outer abominations, outer mutants, or outer spawn and chant from text; +1 bonus on formula ability checks per 2)

Formula Ability Checks: Intelligence (Arcana) or Wisdom (Yog-Sothothery) DC 34, Intelligence (Arcana) or Wisdom (Yog-Sothothery) DC 34, Intelligence (Arcana) or Wisdom (Yog-Sothothery) DC 34

Formula Backlash: 14d4 psychic damage to primary caster and 14 psychic damage to each secondary caster

Formula Failure: Second-degree insanity or indefinite madness, and five levels of exhaustion

Duration: Instantaneous

You summon Yog-Sothoth through the gate into your plane of existence, where its influence manifests centered on the gate. Yog-Sothoth can then allow through whatever other creatures or other Elder Influence from beyond it desires.

The primary caster must be an outer spawn of Yog-Sothoth.

Halfway through the spellcasting, a 20-foot-radius circle of eldritch fire appears centered on the gate. This fire lasts for the duration and deals 6d6 fire damage to any creature that begins its turn in it or passes through it. At the completion of the spell, Yog-Sothoth appears unharmed amid the flames.