Corrupt Soul

Choose one target that you can see within range. They must make a Constitution saving throw against your Spell Save DC. On a failed save, they take 4d8 Fire and 4d8 Necrotic damage. On a successful save, they take half damage. If a creature is killed by this spell, their soul is bound to you.

At Higher Levels: When you cast this spell using a spell slot of 5th level or higher, the damage is increased by 1d8 per damage type for every slot level used above 4th.