Death Wind's Heart

The fossilized heart of The Enduring Wind, a dragon necromancer prepared to wipe out a Giant city in the draconic cataclysm, but who was killed before unleashing their spell. The necromantic energy, stored but never used, kept the creature animated but mindless over the millennia, the spell within still able to be cast.
While touching the heart, a number of spellcasters can pool their power to cast The Death Wind. They must expend a total of 20 levels worth of spell slots, and each must be capable of casting 5th level spells. After the 1 minute casting time, one of the casters must make a DC 20 spellcasting modifier check. If the check is failed, the spell slots used are expended, and all the casters take 1d10 necrotic damage for each level of spell expended. If the check succeeds, the spell slots are expended, the heart crumbles to dust, and the spell is cast using the lower spell save DC of the casters, at a target point chosen by the caster who made the check.

The Death Wind

9-level Necromancy

Casting Time: 1 minute

Range/Area: 10 miles

Components: V, S, M

Materials: The fossilized heart of The Enduring Wind

Duration: Instantaneous

When cast, choose a point within range with clear line of sight to the caster or casters. A storm of necromantic energy erupts at the chosen point, bursting outwards in a black and green wind of energy that reaches a mile away from the origin within seconds.
All creatures within a mile of the origin must make a Constitution saving throw, suffering 8d6 necrotic damage on a failed save, or half damage on a success. Creatures killed by the spell are raised 1 hour later as zombies, under no creatures control. All nonmagical plants within range are killed. Organic matter such as wood and bone is rendered brittle and structurally unsound, and matter such as fabric or food begins to rot.

Available for: Elder Wyrm