Survival in New Vance

Reaction, which you take when a hostile creature within 30 feet of you hits an ally with an attack. You deploy a specialized nanite injector, targeting the attacking creature's cellular structure. The creature must make a Constitution saving throw. On a failed save, the nanites rapidly accelerate cellular breakdown, dealing 4d8 necrotic damage and imposing the poisoned condition for 1 minute. On a successful save, the creature takes half damage and is not poisoned. The effects of the nanites last for the duration or until the poisoned condition is removed.