You have learned to modify your body to create maximum power output from your core. Monks that follow this monastic tradition are typically warforged that have augmented their bodies to perform better in combat scenarios but in some worlds, even organic humanoids have found a way to accomplish these feats. 

Power Die

The amount of power generated from your core can now be utilized to fuel you while in a power generating mode. You gain access to a pool of power dice equal to your proficiency modifier and is increased when you gain a new monastic tradition feature. The dice size is equal to your martial die and can be rolled for a variety of options. This feature gains more options at 6th, 11th, and 17th level. This pool is replenished when you activate the critical status.

Invigorating Steam.

The extra power generated from your core can be channeled into your physical prowess. Whenever you make a check or saving throw using Strength or Dexterity you can roll a power die and add it to the check or saving throw's total.

Subcritical Status

3rd-level Way of the Steam Core feature

With modifications made to your core, you are able to enter a state of high pressure, giving you increased strength and agility. As a bonus action, you can spend 2 ki points to enter this status. When you do so, each creature within 10 feet of you must succeed on a Dexterity saving throw or take fire damage equal to two rolls of your Martial Arts die.

While in this status you gain the following benefits if you aren't wearing heavy armor:

• You have resistance to bludgeoning, piercing, and slashing damage from non-magical sources.
• You gain access to a pool of power dice equal to your proficiency modifier. The dice size is equal to your martial die and can be rolled and be used for a variety of features. This pool is replenished when entering a new critical status

If you are able to cast spells, you can't cast them or concentrate on them while in this status.

Subcritical status lasts for 1 minute. It ends early if you are knocked unconscious or if your turn ends and you haven't attacked a hostile creature since your last turn or taken damage since then. You can also end it on your turn as a bonus action.

Steam Burst

6th-level Way of the Steam Core feature

Steam Burst

Steam boils and escapes around your body, powered by the raging inferno that is your core. While in critical status, as a bonus action, you can expend one of your power die. You gain temporary hit points equal to the power die plus your wisdom modifier. While you still have these temporary hit points any creature that hits you with a melee attack takes fire damage equal to your Wisdom modifier.

Supercritical Status

11th-level Way of the Steam Core feature

Channeled Surge

You have learned to channel the steam pouring from your body and can direct it towards foes. Whenever you hit with a melee attack you can choose to expend a power die and add the number rolled to the damage of the attack. This damage is fire damage. Your core is now burning at high temperatures and pressures, as a result while in critical status you gain the following benefits:

• Your resistance to bludgeoning, slashing, and piercing damage now includes magical sources.
• You have resistance to fire damage
• Any fire damage you deal as a result of any of these features ignores resistance and treats immunity as resistance.

Ultra-supercritical Status

17th-level Way of the Steam Core feature

Meltdown.

You can bring the power your core is generating out in one burst to punish your enemies. You can choose to end your critical status early as a bonus action. If you choose to do so all remaining power dice can be rolled. Any creature within a 10ft sphere centered on yourself needs to make a Dexterity saving throw, DC being you ki save or take total dice roll in fire damage on a failure or half as much on a success. The amount of energy coursing through would be too damaging to use again without rest, as a result, once you use this feature it can't be used again until a long rest.

You also gain the following benefits while in critical status:

• You gain immunity to fire damage.
• If you start your turn without a power die you can spend 1 ki point to replenish one to the pool