Thundercrash

You channel the power of the storm and turn yourself into a living missile, charged with electricity. When you cast this spell, you gain a flying speed of 60 feet. However, upon casting the spell, you must use all your movement each turn. If you slam into something while flying, the spell ends, and you discharge all the arc energy you're channeling. The creature/object you slammed into takes 4d8 bludgeoning damage and 6d8 lightning damage. Anything within 40 feet of the creature/object you slammed into must make a Dexterity saving throw, taking 4d8 lightning damage on a failed save, and half as much on a successful one. If the three round duration is up and you have not slammed into anything, the spell doesn't immediately end. Instead, you lose your flying speed and begin falling at a rate of 20 feet per round, causing the same effect upon landing as slamming into something, but with only half as much damage. (i.e. 4d8 becomes 2d8 and such.)