Sea of Thought

You cover the area in a sloshing torrent of semi-solidified thought, roughly ankle high. The area becomes difficult terrain, similarly to a shallow bog. Each round that a creature starts its turn in the area, it must attempt a Fortitude save against the shifting waves of thought. On a failure, it takes a –10-foot circumstance penalty to its Speeds until it leaves the area, and on a critical failure, it is also knocked Prone.