Base Class: Monk
Parry! Counter! Combo!
Reader of Battle
You gain proficiency in the Insight skill if you don't already have it. Additionally, you can use your Wisdom modifier in place of Intelligence when making a check to recall or deduce information about a creature's fighting style, tactics, or combat history.
Broken-Fist Parry
When a creature hits you with a melee attack, you can use your reaction to halve the damage you take, then reduce the remaining damage by 1d6 + your Dexterity modifier. If this reduces the damage to 0, you deflect the attack entirely, and can make one unarmed strike against the attacker as part of this reaction.
Killing Intent
You gain a pool of d4s, empty at the start of each combat. You gain one die in this pool whenever you either fully deflect an attack with Broken-Fist Parry or are missed by an attack from a creature you can see. This pool's maximum is equal to your proficiency bonus. Once per turn, when you hit a creature with an unarmed strike, you can expend any number of dice from this pool, dealing that much extra damage to the target. Additionally, whenever you deflect an attack with Broken-Fist Parry, the attacker has disadvantage on the next attack roll it makes before the end of its next turn.
Untouchable
Your Killing Intent pool's maximum increases to twice your proficiency bonus. Additionally, when a creature you can see hits you with a melee attack, you can spend 1 ki point as a reaction to take no damage from that attack and add two dice to your Killing Intent pool.
Apex Predator
As a bonus action, you can enter a feral state for 1 minute. While in this state, the dice in your Killing Intent pool are d8s instead of d4s, your unarmed strikes count as magical for the purpose of overcoming resistance and immunity, and you have resistance to bludgeoning, piercing, and slashing damage from nonmagical attacks. If you reduce a creature to 0 hit points with an unarmed strike while in this state, your Killing Intent pool immediately refills to its maximum. You can use this feature once, and regain the ability to do so when you finish a long rest.