Biuntalar’s disturbed Weave

This is the second creation spellwoven by Diatrus Biuntalar. 

You disturb the magical weave around a target within range, hindering its ability to cast spells. Spell attacks by the target are made with disadvantage. Similarly, If the target casts a spell that forces a saving throw, the saving throws against it are made with advantage.

At the end of the targets turn, it can try to withstand your magical prowess. Roll opposed arcana checks to see who can exert more control of the magical weave. If the target succeeds, the spell ends. 

At Higher Levels. For each two spell levels above 4th level, you can designate a school of magic that is entirely suppressed by the weave disturbance.