This spell attempts to wrench the blood in a foe's body. Choose one creature you can see within range. That creature must make a Constitution Saving Throw. On a failure, it takes 1d4 poison damage and is poisoned until the end of your next turn or the spell ends. While poisoned in this way, it has disadvantage on saving throws made to maintain concentration and its speed is reduced by half.

This spell is a Blood spell in addition to its other school. Creatures without blood are immune to this spell. Saving throws to maintain concentration caused by this spell have disadvantage.

At 5th level, the spell deals 2d4 necrotic damage. At 11th level it deals 3d4, and at 17th level it deals 4d4.