Deadfall

You run your magical hands on the string of your bow, the string glows a purple light and spreads to the arrow itself. When fired, the arrow will pull any creature, huge or smaller, within a 15 ft sphere to the point where the arrow was fired. Creatures affected have to make a STR saving throw or be grappled by the void tendrils of the arrow for the duration. On a successful save, the target is in difficult terrain but still takes all other effects of the spell. 

Any attack made against the creatures within the sphere add a d4 to any damage. Spell can only be cast once per long rest.

At higher levels, add a d4 for each spell level.