Cainhurst's pit of Shifting Earth

 Within a range of 100 ft. That you can see, Creates a 25 foot radius of Earth that becomes like quick sand, dragging opponents into the center of the circle. Retraining opponents on a failed Strength saving throw. On a success the take half damage and are not retrained. At the end of their turns they can make a strength saving throw, on success they are no longer restrained and have their movement speed halved as long as they are in the radius.

     Any opponent crossing over this space once the spell is cast has to make a strength saving throw.