Javelin of Lightning

Damage: 1d6 Damage Type: Piercing Properties: Range, Thrown Range: 30/120
When you huck it and speak its Command word, it transforms into a bolt of lightning, forming a line 5 feet wide that extends out from you to a target within 120 feet. Each creature in the line excluding you and the target must make a DC 13 Dexterity saving throw, taking 3d6 lightning damage on a failed save, and half as much damage on a successful one. (Level 5 it jumps to 4d6) The Lightning Bolt turns back into a Javelin when it r