Blood Tithe

You release a blood whip towards one creature within range. Make a ranged spell attack against the target. On a hit, the target takes 2d6 necrotic damage and you gain 1d4 temporary hit points.

Empower. When you cast this spell you can choose to expend one of your Hit dice to empower it. If you do, the temporary hit points die becomes a d8.

At Higher Levels. For every 2 levels of upcast, the necrotic damage increases by 2d6 and the temporary hit point dice count increases by 1.