The Way of the Cogmaster

Cogmaster monks hone their techniques not in a monastery, but a forge; They are smiths, tinkers, and craftsmen who use their brain to enhance their brawn. Through the use of prosthetics and attachments, they alter their forms into the ultimate combination of man and machine. A Cogmaster monk sees his own body as the ultimate canvas to unleash his wildest creations

Ever More Prosthetics

When you reach sixth level, choose one of the three options presented to you for a prosthetic

 

AI sensor

You gain blindsight to a range of 15 ft. You are instantly alerted to any movement within 40ft. You know the size and number of the creatures, but not their direction or features. You are awoken by any unexpected movement in this range.

Oil sprayer

As an action for 1 ki point, you may activate the oil sprayer. Until the end of your next turn, every space you leave is treated as if it were under the effects of the Grease spell. You may coat a space within 10 feet in exchange for an unarmed strike.

Serum Injector

When below half of your hit point maximum, you can spend a ki point to gain 2d4 temporary hit points each turn for 1 minute. You can add your proficiency bonus in poison damage to every attack until the end of your next turn. Every other round, you must make a Constitution Saving throw (dc:14) or gain one level of exhaustion.

Proficiency

when you choose this subclass at third level, you gain proficiency in Tinker's tools

Malfunction

When you roll a 1 on an ability check, attack roll, or saving throw, your mechanical enhancements malfunction. Roll a d12 to determine the malfunction from the table below:

1 Steam Leakage: Steam vents uncontrollably from your mechanical enhancements, blinding all creatures in a 10 foot cube for 1 minute or until dispersed by heavy wind. This cube moves with you. A successful check with Tinker's Tools will end it early.

2 Cog Jam: A crucial cog in your mechanism gets stuck: your movement speed to be halved until the end of your next turn.

3 Hydraulic Failure: Your joints lock up: you are restrained until the end of your next turn.

4 Overcooked: Your inventions overheat: you suffer the effects of the Heat Metal spell until the beginning of your next turn

5 Gear Grind: Your gears get jammed, making your actions clumsy. Your next roll using the same stat as the critical failure also fails (if made within 1 minute)

6 Rust Infestation: Rust quickly spreads across your metal components, causing disadvantage on Dexterity saving throws until the rust is scraped off (requires an action).

7 Piston Misfire: One of your mechanical limbs misfires, and you roll a d8 to determine the direction your next attack is made in

8 Power Surge: Your energy reserves surge, making a bright flash of light and deafening noise. You and all creatures within 10 feet must make a Constitution saving throw or be blinded and deafened until the end of your next turn.

9 Steam Exhaust: Your steam exhaust port releases unexpectedly, propelling you 10 feet in a random direction determined by rolling a d10. On a 10, you are knocked prone

10 Accidental Combustion: Your fuel tank explodes: cast Thunderwave centered on yourself

12 Engine leak: Your engine leaks oil: the Grease spell is cast centered on yourself

The dc for every check and save is 14

 

Hydraulic Movement

When your reach level 11 in this class, you can add your Intelligence modifier (minimum of +1) to Initiative rolls and Strength and Dexterity saves. When you are hit with a melee attack, you can spend a ki point to jump 1/3 your walk speed (rounded down)

Prosthetics

When you choose this subclass at level 3, pick two of the three options provided below.

Overdrive

Once per turn when you have 0 ki points, you may make an attack targeting yourself. On a hit, you take lightning damage equal to 1 roll of your martial arts die and gain 1 ki point. On a miss, you take half damage.

This damage ignores resistance, immunity, and alternative hitpoint pools

When you reach 11th level, you may subtract your intelligence modifier (minimum of 1) from this roll

Protective field

You have a pool of temporary hit points equal to twice your monk level multiplied by your proficiency bonus.

As a reaction, you may reduce incoming damage by one roll of your martial arts die. This damage instead subtracts from the pool. You take any remaining damage.

The pool regenerates entirely once every 24 hours.

When you spend a hit die, the shield regains half of the roll in hitpoints.

This may be used as part of your reaction for Deflect Missiles.

Spring Loaded Strikes

When you make a flurry of blows, your strikes may attack another creature adjacent to your intended target for half-damage. If you choose to attack only one target, you may move 10 ft in any direction on a hit, provoking no attacks of opportunity.

Divide and Conquer

When you have reached 17th level, your body has become so altered that it can exist independently of your head.

You are considered both a construct and your original creature type (see Fey Ancestry).

As an action, you may divide yourself into two parts: your head and your body. The cranium assumes the statblock of a Homunculus, while keeping your intelligence, wisdom, and charisma scores. It has 1/4 of your current hitpoints. Your body keeps your original statblock, but is blinded and deafened if your head is more than 30 ft from it or something comes between them.

If either part is destroyed, it can be rebuilt in four days' work (assuming 8hrs of work per day) for 75 gold pieces. Using Greater Restoration or Regenerate removes the gold cost and one day's work. 

If both are destroyed, you die.