This is a JoJo reference.

Monks trained in the Way of the Ripple have the ability to conduct magical energy of sorts - this magical energy known as 'Ripple Energy' is a direct manifestation of one's Ki. 

The Way of the Ripple is a path that one follows to weaponize their own Willpower, Resolve, and even Vitality. The Way of the Ripple grants many powers which often end in equivalent exchange. You must be willing to make sacrifices in order to achieve your goals, in order to vanquish your foes. Even weaponizing your own Heartbeat. You are dangerous to be left alive, because the fact that your blood still flows and you still breathe could be the very end of those who challenge you. The only one who stands in your way of victory is Fate.

Ripple Energy uses the very energy of Life itself. In order to utilize 'Ripple Energy', you must at least have flowing Blood / Be able to Breathe. If you fail to meet both requirements then you cannot harness Ripple energy. Users of the Ripple who become Undead later on, through a Curse, or a Magical Effect of sorts cannot use 'Ripple Energy' until they are living again, if they do, they take 25 Radiant Damage (this can also be affected by Vulnerabilities) every turn of usage. HOWEVER, It is important to note that you should Subtract your Constitution Modifier from the Damage taken.
If you reach 0 HP from this effect, you immediately die and turn to ash. Only being able to come back via. True Ressurection (and you will be considered non-undead if revived by it). It is common for users of the Way of the Ripple to willfully cause this, as being an Undead would directly betray the Way of the Ripple, as the Ripple is the usage of "Life Energy", and Undead are completely devoid of life.

Here is a converter for the Radiant Damage taken as an Undead (per turn).

• Con x 2 - Damage = Damage Taken.
  (Example: User's Constitution Modifier is +1
  1 x 2 - 25 = 23 Radiant Damage Taken.)

 (Disclaimer: This Subclass is balanced around situational circumstances and level. If you play a character with this Subclass, due to the Ripple Energy actions, you will be more effective under certain circumstances, such as with the Turquoise Blue Overdrive action, or fighting Undead. That being said, you will be quite versatile. Additionally: You will need a high Constitution as this Subclass requires it for many features. Upon leveling up to levels 11 and 17, you become incredibly powerful and versatile. All of the Features gained in this Subclass grant you unique actions per feature, make sure to look at those before deciding whether to allow this in your campaign or not, as they dictate the power of the subclass more than the Features do. This class is also incredibly complicated and has a ton of rules and caveats so please ask someone to help you understand if you are confused about something. Please give me feedback on this Subclass, let me know if it's too Complex, Underpowered, Overpowered, and whatnot.)

Ripple Energy

You gain the ability, through extensive training to use "Ripple Energy".

This involves learning Ripple-based attacks, and the ability to imbue Ripple Energy through your body and objects around you to gain certain effects.

Heritage of the Ripple

You become familiar with the study of Ripple Energy.

• You now have prolonged aging, you age 3x Slower than your current Race's lifespan.
• You gain 3 more Actions for the Ripple Energy feature.

Ripple Potency

You have become an Expert in Ripple Energy.

• All Ripple Moves deal double damage.
• You gain 1 new Ripple Energy feature.
• If you are carrying any sort of container with Liquid, or are within 5 ft. of Liquid, you gain Blindsight up to 25 ft.
• Zoom Punch now automatically activates the Stunning Strike feature.
• While Charging Ripple Energy, you gain Resistance to Bludgeoning, Piercing, Slashing damage, but any attack which forces you to take Fire, Cold, Lightning damage becomes 2x as Likely to hit. (Advantage on Attack Rolls, and Disadvantage on Saving Throws to resist those effects)
• You gain a passive resistance to Necrotic damage.
• While Charging Ripple Energy, you become completely Immune to Necrotic damage unless you take Cold damage, then your Ripple Energy Charging immediately ends.

Unbound Resolve

Your resolve may shine through even in your darkest times.
Even when Fate is against you, your training in Ripple Energy has made you more tenacious.

Instead of failing 2 Death Saving Throws after rolling a Natural 1, you only fail a single Death Saving Throw when a Natural 1 is rolled. You take half damage from effects that are a result of you suffocating or being unable to breathe, e.g: drowning.

Ripple Overdrive Barrage

You are now capable of performing a "Ripple Overdrive Barrage".

Flurry of Blows automatically has the "Ripple Overdrive" feature benefits, and you can make 1 additional Extra Attack per turn with this feature.

Master of the Ripple

You have Mastered the Way of the Ripple, you gain the following features:

• You gain 3 new Ripple Energy features.
• While using Ripple Overdrive, or while making a Ripple Infused attack with Ripple Charging, you are able to create a "Ripple Chain", choose a creature within 10 feet of a creature that you strike on the same turn, they take half the damage you dealt to the original target, and this feature can continue, until you run out of chosen targets. You do not have to choose a target, and each time you hit a creature, the damage halves.
• You gain a psychic view into your opponent's defenses, you immediately learn their HP, AC, Vulnerabilities, and Resistances if you have attacked them with Ripple Energy.