Blue-Lightning Blade

This spell allows you to attack a creature within range using an enchanted weapon. If the attack hits, the target takes normal weapon damage and you can create a blue lightning arc to strike a second creature within 5 feet, causing lightning damage equal to your spellcasting ability modifier.

The spell's damage increases with your level. At level 5, the melee attack adds 1d8 lightning damage to the target, and the lightning damage to the second creature increases to 1d8 + your spellcasting ability modifier. At levels 11 and 17, both damage rolls increase by 1d8 (2d8 and 3d8 respectively).