Choose one creature you can see within range. The target must make a Constitution saving throw. On a failed save, it takes 4d6 Fire or Necrotic damage; you choose the damage type when you cast the spell. On a successful save, it takes half as much damage and the spell ends.
On each of your turns for the duration, you can use a Bonus Action to force the target to repeat the saving throw. On a failed save, it takes 2d6 damage of the chosen type and has disadvantage on the next attack roll it makes before the start of your next turn. On a successful save, the spell ends.
Creatures without blood or comparable vital fluid have advantage on the saving throw.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the initial damage increases by 1d6 for each slot level above 3rd.
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