Comments from the Nails: if any of you remember the classic games Dungeon Keeper and Dungeon Keeper 2, you might remember a creature called the 'dark mistress'. Recently, I got to wondering if I could implement Dungeon Keeper in Dungeons and Dragons (the overlap in the names being an obvious prompt), and I figured that the mistress must be a monk - she's fast, fights with her hands, doesn't wear armor, casts a couple of spells and is very dedicated to her rituals.
Way of the Wheel
In the dank and reeking donjons and gaols of countless towns, forts and temples, an order of monks plies their trade. These are not the somber and disciplined ascetics one would normally associate with the better-known monasteries of the world, however. No, these leather-clad lunatics are dedicated to interrogation and torture, gleefully extracting confessions, repentance and even loyalty from their victims.
Whether by burning brand, electric shock, rack or Catherine wheel, the Monks of the Wheel are unrivaled in their chosen profession, and command a mighty reputation among the warlords, tyrants and monsters who employ them. No evil overlord gets far without the dedicated - and scarily eager - service of one of these masters of pain.
you choose this tradition at 3rd level, you learn the techniques of the Way of the Wheel, including their signature weapon. You can choose to deal slashing instead of bludgeoning damage for your unarmed strikes. If you deal slashing damage to a target that is not a construct or undead, you can also spend 1 ki point to make the target bleed. A bleeding target loses 1d4 hit points at the start of each of its turns until it uses an action to staunch the bleeding. While a target is bleeding, it can't regain lost hit points.
6th level, you can apply double your proficiency bonus to any ability check relating to torture or torture devices.
In addition, you learn the shocking grasp cantrip, which you can cast in place of one of your attacks when you take the Attack action on your turn. Wisdom is your spellcasting ability.
Addicted to Pain
11th level, you are so accustomed to pain that enter a rapturous frenzy when wounded. Whenever you take the Attack action on your turn while you have fewer than half of your maximum hit points, you can make one additional unarmed strike.
When you reach 17th level, you can spend 5 ki points to cast dominate person, using your ki save DC.