Great Weapon Master

You've learned to put the weight of a weapon to your advantage, letting its momentum empower your strikes. You gain the following benefits:

• On your turn, when you score a critical hit with a melee weapon or reduce a creature to 0 hit points with one, you can make one melee weapon attack as a bonus action.
• Before you make a melee attack with a heavy weapon that you are proficient with, you can choose to take a -5 penalty to the attack roll. If the attack hits, you add +10 to the attack's damage.

name = 'Great Weapon Master'
description = "***Feat: Great Weapon Master.*** You've learned to put the weight of a weapon to your advantage, letting its momentum empower your strikes."
def prereq(npc): return True
def apply(npc):
    npc.bonusactions.append("***Great Weapon Master.*** When you score a critical hit with a melee weapon or reduce a creature to 0 hit points with one, you make one melee weapon attack.")
    npc.actions.append("***Great Weapon Master.*** Before you make a melee attack with a heavy weapon that you are proficient with, you can choose to take a -5 penalty to the attack roll. If the attack hits, you add +10 to the attack's damage.")