Blood Strike

When a creature that you can see strikes you with a melee or ranged weapon attack, you can use your reaction to cast this spell. Your blood lunges towards the creature, dealing 2d6 points of piercing damage. For the duration, the creature must make a Constitution Saving Throw at the start of each of its turns. On a success, the spell ends. On a failure, it suffers 2d6 points of Necrotic damage.

For each level of spell slots used to cast this spell beyond 3rd, the Piercing and Necrotic damage increase by 1d6.