Borrow Life

A ray of pitch black streaks toward a creature within range. Make a ranged spell attack against the target. On a hit, it takes 1d6 necrotic damage. A ray of sunlight then streaks towards one of the caster's allies and heals them for half of the damage dealt, rounded up. The sunlight streak will always target the caster's ally closest to the original target, and will only target the caster's allies who are within 15 feet of the original target. 

The spell's damage increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).