Ravenous Darkness

You create a shroud of magical darkness that feeds on those inside it. This globe of pure darkness is identical to that created by a 4th-rank spell. Blunt, gnashing teeth made of shadows gnaw at the creatures within. Make a spell attack roll against the Fortitude DC of each creature in the area. Any creature that fails takes 4d6 bludgeoning damage as teeth attach to it. While the teeth are attached, it takes a –10-foot circumstance penalty to its Speeds and can't Step. Whenever a creature ends its turn in the area, the teeth attempt to attach to that creature if they haven't already, and they deal 1d6 bludgeoning damage to any creature they're already attached to. The shadowy teeth become unattached from any creature that leaves the area but can't otherwise be detached from a creature while that creature remains in the area. You can Dismiss the spell.