Walton's wall of wards

Tracing the air in front of them the caster of this spell draws out a large rectangle in front of them. Chose two points within range of this spell. A 25 foot long and 15 foot high intangible wall of swirling magical wards appears. When you cast this spell choose a side to be dampening, the other will be enhancing. When a spell is cast on the dampening side of the wall and targets a space behind the enhancing side any damage it would do is reduced by 4d8. If the spell would not do damage but does incur a saving throw the saving throw is made with advantage. Alternatively, if a spell is cast on the enhancing side and targets a creature on the dampening side the damage of the spell is increased by 2d8. If the spell does not do damage but incurs a saving throw the save is made with dissadvantage.