Lightning Javelin

This javelin is a magic weapon that returns
immediately after being thrown.
Action: When attacking, command it to become
a lightning bolt, 5 feet wide, from you to a target
within 120 feet. Each creature in the line must
make a DC 13 Dexterity saving throw:
4d6 lightning damage on a fail; half on a success.
THEN, make a ranged weapon attack against the
target. On a hit, the target takes damage from the
javelin plus 4d6 lightning. This power recharges
at dawn.