Essence transfer

You attempt to launch a spear of energy into a target, and a willing ally other than yourself who must both be within 30 feet of you and each other. Make a ranged spell attack against the target. On hit deals 1d8 necrotic damage to the target and heals the linked ally by the damage dealt. You can use your action on each of your turns to automatically deal 1d8 necrotic damage again and heal the ally by the same amount until the spell ends, either target dies, or you lose concentration.

When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d8 for every two slot levels above 2nd.