You imbue yourself with the swift rage of a tempest, turning your movement into a storm of thunder and lightning. Until the end of the turn, you gain 40 feet of additional movement, your movement doesn’t provoke opportunity attacks, and you can make up to four melee weapon attacks (no action required), though each must be against a different target. On a hit, these attacks deal an additional 2d4 lightning damage.   At the end of the turn, a thunderous boom follows in your wake that can be heard 2,500 feet away. Each creature you attacked with this spell must make a Constitution saving throw. On a failure, a creature takes 2d4 thunder damage and is knocked prone. On a success, a creature takes half as much damage and is not knocked prone.