Mage Slayer

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

• When a creature within 5 feet of you casts a spell, you can use your reaction to make a melee weapon attack against that creature.
• 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 5 feet of you.

name = 'Mage Slayer'
description = "***Feat: Mage Slayer.*** You have practiced techniques in melee combat against spellcasters."
def prereq(npc): return True
def apply(npc):
    npc.reactions.append("***Mage Slayer.*** When a creature within 5 feet of you casts a spell, you make a melee weapon attack against that creature.")
    npc.actions.append("***Mage Slayer.*** 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.")
    npc.traits.append("***Mage Slayer.*** You have advantage on saving throws against spells cast by creatures within 5 feet of you.")