Synaptic cascade

You forcefully link the minds of your enemies into a single, agonizing network. Choose a creature you can see within range. That creature, and every enemy within 60 feet of it, must make an Intelligence saving throw.

On a failed save, a creature takes 12d10 psychic damage and is paralyzed for the duration. On a successful save, a creature takes half as much damage and is not paralyzed.

After this initial blast, the linked minds suffer from lingering psychic feedback. While the spell lasts, whenever a creature paralyzed by this spell takes damage from any other source, attack, or effect, the mental network flashes with pain: every other creature currently paralyzed by this spell takes psychic damage equal to half of that amount.

A paralyzed creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.