Blue Lightning Blade

You brandish the weapon used in the spell’s casting and make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapon attack’s normal effects, and you can cause Blue Lightning to leap to the target dealing 1d4 lightning damage. 

When casting at a higher level, You may deal an additional 1d4 Lightning damage equal to the spell slots level you cast.