Mage Slayer (Variant)

You have practiced techniques in melee combat against spellcasters, gaining the following benefits:

• When a creature within 30 feet of you casts a spell, you can use your reaction to make a melee weapon attack against that creature.
• You deal additional 1d12 Force damage against creatures concentrating on spells or similar abilities.
• Creatures you attack had disadvantage on the saving throw they make to maintain their concentration.
• You have advantage on saving throws against spells.