Arcane Assassin

You have gained the skills passed down from eras past to combat the warping of reality by arcane practitioners, gaining the following benefits:

• When a creature you can see, casts a spell, you can use your reaction to make a melee or ranged weapon attack against that creature.
• If the creature is dealt damage by the reaction attack and the creature is casting a spell of 3rd level or lower, its spell fails and has no effect.
• If it is casting a spell of 4th level or higher, make an ability check using your Strength or Dexterity bonus. The DC equals 10 + the spell's level. On a success, the creature's spell fails and has no effect.
• When you damage a creature that is concentrating on a spell, that creature has disadvantage on the saving throw it makes to maintain its concentration.
• You have advantage on saving throws against spells cast by creatures within your melee range you can see.