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 an additional 1d10 force damage against creatures concentrating on spells or similar abilities. Creatures you attack have disadvantage on the saving throw they make to maintain their concentration.
  
  
• You have advantage on saving throws against spells.