Dispelling Assault

You attack with such fury that your enemy’s magical defenses wither and fail.

When you activate this technique, you take the Attack action and make a weapon attack, as well as any additional attacks granted by Extra Attack. Until the start of your next turn, your weapon attacks score a critical hit on a roll of 19–20, and when you score a critical hit against a creature any spell of 3rd-level or lower on the creature ends. 

If you already have a feature that increases the range of your critical hits, your critical hit range increases by 1 (maximum 17–20).