Vakri's Weave

You focus on an area you can see within range. The air shimmers slightly purple in a 60ft. cube and fogs the mind of anyone trying to cast a spell within that area. To cast a spell from within the area, a creature has to succeed on a Concentration check equal to your spell save DC. On a failure, the spell fails, but the spell slot is spent. On a success, the spell is cast normally.

Creatures inside this area have disadvantage on maintaining concentration on spells.

You can move the cube up to 20ft. or dismiss it as a bonus action.