Arcing Smite

The next time you hit a creature with a melee weapon attack during this spell's duration, your weapon scatters arcing lightning and the attack deals an extra (1d6) lightning damage to the target.  For the duration of the spell, as long as your weapon remains within 30ft. of the target, a connection of lightning forms between your weapon and the target. 

At the start of the targets turns, the target and up to one other Creature of your choice within 15ft of the Target take (1d8)Lightning Damage.  If your weapon is ever more than 30 ft. away from the target, the spell ends.

At Higher Levels.  When you cast this spell using a 3rd level spell slot of higher, the spell's initial damage increases by (1d6) and the secondary damage can target one additional Creature for each spell slot level above 2nd.