Arcane Polarity

You surround yourself with arcane energy and use it to change how magic functions against a creature.

One target creature that you can see within range becomes extra vulnerable to spells of a specific school of your choice for a short while. The next time the target has to make a saving throw against a spell of that school, the DC is increased by 2.

At Higher Levels: You can cast this spell at higher levels, for every level beyond 1st, increase the number of targets affected by 1. Each additional target must be within 15 feet of the first target.