Boros' Lightning Helix

A spiraling bolt of divine lightning strikes forth against the enemy. Make a ranged spell attack against a creature within your reach. On a hit, the target takes 4d10 lightning damage, and you regain hit points equal to half the amount of lightning damage dealt. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d10 for each slot level above 3rd.