Thunderous Steps

You can teleport 3 times up to 30 feet from previous location, each teleport leaves behind an explosive blast of electricity that extends 1 ft. in each direction Each creature within range, other than you & allied creatures, must succeed on a Constitution saving throw or take 3d6 thunder damage per "step". On successful save, damage is halfed. 

The spell’s damage increases by 1d6 when you reach 14th level (4d6) and 20th level (5d6)