Weave Blood

You command the betrayal of another being's own blood. One humanoid that you can see within range must make a Constitution saving throw: on a failure, the target is stunned until the beginning of your next turn and takes necrotic damage equal to your hit dice type + your spellcasting ability modifier, as its blood spikes out through its pores and holds it in place. On a success, the target takes half that damage and is not stunned.

At higher levels: When you cast this spell using a spell slot of 4th level or higher, the damage dice increase by 1 for each slot level above 3rd.