Agony Chain

A dark lightning bolt leaps from your finger towards the target, inducing pain and leaping towards another nearby creature. A creature that you target with this spell make a Constitution saving throw. On a failed save, the targets take 5d6 necrotic damage and is stunned until the end of your next turn. The bolt then leaps to a second creature of your choice within 10 feet of the target, which must then succeed on the same save and suffer the same effects. On a successful save, the target takes half as much damage and the bolt doesn't leap to another target. The bolt can only target two creatures, and cannot target the same creature twice.

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the bolt can target another creature for each slot level above 6th. When casting this spell at 9th level, the bolt continues to target creatures even when one succeeds the saving throw, and it can target a creature more than once.