Way of Gore

Monks of the Way of Gore have forgone intricate physical techniques and ancient knowledge, having been altered magically with selective regeneration. They have the ability to regenerate from any injury caused to them, so long as said injury is caused by themselves. A Monk following the Way of Gore might remove his own arm to use as a weapon, or break it at the forearm to use the bone as a sword. Despite not using conventional martial arts techniques, these Monks tend to be very violent and very proficient in using their raw strength. Pain becomes a normality to those following this Way, a feeling that reminds them not of danger, but of power. 

Brutality

When making an unarmed attack, you are able to dismember yourself and depending on the situation, may do more damage than a normal unarmed attack. As a free action at the end of your turn, you may regenerate any damage you've done to yourself. 

If you, for example, use the bones in your arm for piercing or slashing, it would count as a weapon for the purposes of abilities requiring such weapons to activate.

Your blood may also be used as a weapon of sorts. To you, it functions as anyone's blood would, but if ingested by another person, it acts almost like a poison.

At the discretion of the DM, you may be able to add damage to your attacks in this manner by having something like a bladed gauntlet to turn your arm (normally acting similar to a club) into a weapon more akin to a mace.

The exact damage done by attacks using Brutality is ultimately up to the DM, but suggested amounts are:

Arm - 1d8 Blunt

Exposed Arm Bones - 1d8 Piercing/Slashing

Ingested Blood - 1d4 Necrotic

Neoplasm

At 6th level, you gain the ability to heal yourself. As an action, you can regain hit points equal to twice your monk level plus your Constitution modifier. You must finish a long rest before you can use this feature again.

Decay

Beginning at 11th level, your attacks made using Brutality inflict 2d6 necrotic damage on top of the blunt, slashing, or piercing damage normally dealt. 

To The Core

At 17th level, you gain the ability to grapple an opponent and deal a specific attack that is guaranteed to hit, so long as you successfully grapple the target. Using Brutality, you may deal an attack against the grappled target that spreads your blood into their bloodstream, dealing 3d10 necrotic damage per turn. The only way to end this constant damage is to remove the part of the body that has been infected quick enough, or by using a divine or otherwise magical cure. If left untreated for 5 turns, the infected blood will reach the target's heart and subsequently detonate it, killing them. This ability can be only be used once per long rest.