Crown of Calamity

Wondrous item, legendary (requires attunement)

This crown glows with hateful embers. While you wear it, when you are subjected to an effect that allows you to make a Dexterity or Constitution saving throw to take only half damage, you instead take no damage if you succeed on the saving throw, and only half damage if you fail.

Blood and Darkness. Whenever you take damage while wearing the crown, you can use your reaction to create a 15-foot-diameter sphere of magical darkness, centered on you. The darkness remains until the start of your next turn.

Incite Calamity. While wearing the crown, you can use an action to cast one of the following spells from it at 7th level, using a spell save DC of 17: call lightning, fire storm, or insect plague. Once a spell has been cast from the crown in this way, it can't be cast from the crown again until the next dawn, unless that spell also reduced a creature with legendary actions to 0 hit points. If you take damage from a spell cast in this way, you automatically succeed on the Constitution saving throw to maintain your concentration on that spell.

Meteor Cataclysm. If you die while wearing the crown, roll a d20. On an 11 or higher, a single meteor (as if by the meteor swarm spell; save DC 17) descends upon your location. The meteor hits the following round on initiative count 20 (other creatures are magically aware of its approach). If the crown is within the meteor's area when it hits, the crown is destroyed in the blast.

"I have seen the end: I know the song and beat of its breaking heart. Its suffering makes me want to weep until the land is flooded."

This is my grief, and I can make peace with that. There is heartbreak that cannot be mended by time, and we are all most surely out of that."

— Final journal entry of Azos of Three Voices, herald of the dragon queen