Fog From the Void (5e Spell)
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Your word shapes the universe to form a black fog that is impossible to see or hear through.
A black fog covers a square area of 20 feet by 20 feet, blinding and deafening all of those in the fog that do not have Truesight. Additionally, all creatures caught within the area of the fog suffer 8d6 cold, lightning, fire or acid damage which is chosen upon its creation, whenever a creature either begins or ends its turn within the fog. Spells with vocal components still work within the fog. The fog may not be dissipated until the duration of the Utterance completes or a dispell effect targets it.
This utterance cannot be spoken in reverse.
At Higher Levels. When you speak this Utterance using a slot higher than 4th level, the duration increases by 1 turn, the length of each leg of the square increases by 5 feet, and the damage increases by 2d6 per level.