Distorted Terrain

You pick a point within 60ft for the spell to inhabit. 

A imperceivably shift happens in a space of up to 10ft x 20ft. The spell does not permeate walls or other structures and therefore ends where they begin. It is not noticeable from the outside to sight or any nonmagical means of detection.  The terrain within the space is warped as if distorted through funhouse mirrors.  The first time a player enters Distorted Terrain they must make an INT save vs your Spell DC.  On a fail their movement ends and they have disadvantage on all attack rolls until they clear the affected area.  If a creature starts its turn in the distorted terrain they roll an INT save.  On a fail they may only move within the affected area, and have disadvantage on all attack rolls. 

This spell scales at: 

5th Level - 15ft x 30ft

7th level - 20ft x 40ft and additionally creatures that fail have disadvantage on INT saves.

9th level - 30ft x 60ft and additionally creatures that fail have disadvantage on INT saves and take 2d6 psychic damage.