Executioner

I can hang you within an inch of your life. A quick death is a good one.

This feat is intended for an NPC executioner. A character taking this feat is grim and law-abiding seeking out those sentenced for punishment; the Sentence of Death feature might be reserved from them without civic authority.

— I'm happy to be your executioner for today. Perhaps the condemned might make their marks on my rope here? For the children and collectors don't you know, and it would mean a lot to me. Hold on while I measure out your weight and height.

You gain the following benefits.

Ability Score Increase. Increase your Strength score by 1, to a maximum of 20.

Heavy Weapon Mastery. When you hit a creature with a weapon that has the Heavy property as part of the Attack action on your turn, you can cause the weapon to deal extra damage to the target. The extra damage equals your Proficiency Bonus.

Gallows Master. You can use a Rope or Chain as a martial melee weapon. When using this feature, the weapon has the Heavy, Reach, and Two-handed properties, and deals 1d4 Bludgeoning damage on a hit. Each turn you may only use one item in this way using this feature.

Law Before Vengeance. On a hit with Rope or Chain using this feat, you can forgo damage to force a Strength or Dexterity saving throw (DC 8 + Strength modifier + Proficiency Bonus). On a failure, the target is Grappled, and you cannot use this weapon to attack others while the grapple persists.

Sentence of Death. You are a master of ending those who have fallen. When you hit a Prone creature with a melee attack using a Heavy weapon, the attack is automatically a Critical Hit. You can use this feature only once per Long Rest.

That Final Inch. When you reduce a creature to 0 hit points with a weapon that has the Heavy property you can choose to leave the target Stable. Your lawful action is visible to others.