Way of the Volcano

Monks who follow the Way of the Volcano are often Hotheaded, but their rambunctious nature conceals a deadly mastery of explosive force. They thrive in some of the harshest conditions that can naturally occur, with their monasteries often residing within the boundaries of active Calderas. They believe that the strength to master such conditions is the true test of all living things and any who may stand against the sheer might of an erupting mountain may wield it's awesome power for themselves. 

Heat Knuckle

When taking up this tradition at 3rd level your inner fire ignites, enhancing you with a might unlike any other. Whenever you hit a creature with one of your attacks granted by Flurry of Blows, they must Succeed on a Dexterity saving throw or become grappled until the beginning of your next turn. Should the grappled creature fail to break free before your next turn you create a small explosion, causing the grappled creature to suffer your choice of Force or Fire damage equal to one roll of your martial dice.

When this is performed on a creature that is Prone, they are instantly grappled with no saving throw. 

Normal grappling rules apply after the initial grapple. You may choose to not make use of this class feature during Flurry of Blows.

Booming step

Beginning at 6th level, you learn to utilize the explosive force of the volcano in more creative ways. Expending 1 Ki point while making a movement action will allow you to create an explosive force to launch yourself up to 40 feet, but no less than 20 feet, in a direction of your choosing. Any creatures within a 5-foot radius of the launch zone must succeed on a Dexterity saving throw or suffer 2d6 Force damage as well as 1d6 Fire damage or half as much on a success. 

If you land on a creature at the end of your travel, it must succeed on Constitution saving throw or suffer 3d6 Force damage. If the creature is no more than 1 size class larger than you, it will also be knocked Prone upon failing the landing saving throw.

Moving in this way ignores difficult terrain and does not provoke attacks of opportunity. You may launch yourself into the air using this class feature.

The Force and Fire damage of this class feature increases by an additional d6 at levels 8, 11, 14, and 17.

Zero Technique

Upon reaching 11th level, your inner fire becomes powerful and difficult to contain. On your turn you are able to declare the use of Zero Technique, and upon doing so your body will erupt with violent force and all creatures within a 25-foot radius must succeed on a Constitution saving throw or suffer Fire damage equal to nine rolls of your martial dice or half as much damage on a success. You may expend Ki points to increase the damage of Zero Technique by one martial dice per Ki point spent.

Additionally, Using Zero Technique will force you to succeed on a Constitution saving throw or take damage equal to your Monk level and be stunned until the end of your next turn. The DC of this saving throw is 5 + half of your Monk level. Being damaged in this way cannot take you below 1 hit point but a minimum of 20 hit points are required to use it.

The Usage of Zero technique cannot be declared if an Attack or Bonus action have been taken during your turn. 

Krakatoa

At 17th level, your very soul burns red hot, it's loud roar tells you to grasp victory! When making an attack action, you are able to expend 3 Ki points to infuse the attack with a fierce and mighty flame. Should the attack hit; the target creature must succeed on a Constitution saving throw or suffer 1d100 + your Wisdom modifier Fire damage and be Deafened until the end of your next turn. Additionally, all creatures within a 10-foot radius must succeed on a Constitution saving throw or suffer 1d20 + your Wisdom modifier Force damage. 

You may expend additional Ki points to increase the difficulty of the saving throw by +1 per 2 Ki points used.