Executioner

For the archetypal Executioner, every fight is an unfair one. They specialize in defeating many opponents as quickly as possible and many times all in the same blow. An Executioner doesn't enjoy violence but they are always prepared for it. You use your strength when calculating your save DC.

Cleaving Attacks

Beginning when you choose this archetype at 3rd level, If you are using a slashing weapon you can use an melee attack to strike multiple opponents. If you hit when making an attack during your attack action another creature adjacent to the original target and within your reach takes half of the damage dealt to the original creature. You can use this ability once per attack action. 

Morbid teachings

You may have learned how to treat wounds at a morgue or in the midst of battle but no matter how you learned it, it was a skill worth learning. You gain proficiency in the medicine skill.

Showstopper

Starting at 7th level, when making a cleaving attack on a success you reduce the cleaved creature's movement to zero.

Improved Cleave

Starting at 7th level, your cleave attacks can affect an additional creature. Also, you can cleave against targets that are not adjacent to each other but are within your reach.

Bloodletter

At 10th level, Once per creature, you can wound the target when you hit a creature with an attack. At the start of each of the wounded creature's turns, it takes 1d8 necrotic damage, and it rolls a Constitution saving throw at the end of its turn, ending the effect on itself on success or after 1 minute.  You use your strength when calculating your Save DC.

You have your proficiency amount of uses per long rest.

Slayer

 At 15th level, You become a bender of steel and fury. When making a cleaving attack, all creatures you choose within your reach are affected.

Waking Gilatine

Starting at 18th level, your weapon attacks are considered to be a critical hit on wounded creatures.