Acceleration off speed

As a bonus action you accelerate gaining double movement speed for one round. However while in this accelerated form you can walk/run through your target stacking Accel stacks on the targets your moving through too a maximum of 2 stacks per target. 1 stack is equal too 1d8 force dmg becoming 2d8 if you have moved through him 2 times before the end of you turn. At the end of your turn everyone that has a stack on them has to make a dexterity save equal to your spell save dc and on a fail the target takes the full amount of damage. If the targets succeeds the damage they take is halfed.

This stack limit increases by 1 for each level you up cast it. At the end of your turn you each creature that has gotten a stack on them.