Way of the Changeling

Monks of the Way of the Changeling have an innate connection to other life forms.  So much so, that they have developed a way of honing in on the ki of others, copying it, and expressing it as their own.

Morphological Flux

Starting when you choose this tradition at 3rd level, you've mastered the art of attuning to the ki of other living beings. You can spend ki points to morph into beings you have attuned to.

In order to attune the ki of another, you must make physical contact and succeed a concentration check. The DC is determined my several factors: the base is 10. For every size smaller than your own, subtract 1. For every size larger than your own, add 2. If the creature is friendly towards you, subtract 2. If the creature is not friendly towards you, add 2. If the creature is submitting to the attunement, subtract 5. If the creature is openly aggressive or in combat with you, add 5. If the creature has a different Con score than you do, subtract the difference if yours is higher, or add the difference if the creature's is higher.  You may spend ki points to gain advantage on this concentration check: 1 point for sizes tiny and small, 2 for size medium, 3 for size large, 4 for size huge, 5 for size gargantuan.

You may attempt to attune to any living creature. You can only be attuned to 3 creatures at a time. If you would like to attune to a different creature once you have reached 3, you can do one of two things: you can spend 10 minutes meditating to choose which attunement to dispel. Or when you attune to a new creature, this automatically replaces the first attuned creature of your current 3. Your number of attuned creatures becomes 5 at 6th level, 7 at 11th level, and 10 at 17th level.

When you attempt to attune to a creature, that creature must make a constitution saving throw against your ki save DC or else be incapacitated until the end of your next turn.

In order to morph into a creature, you have attuned to, you must spend ki points and time. For sizes tiny and small, you must expend 1 ki point. For size medium, 2. For size large, 3. For size huge, 4.  For size gargantuan, 5. If in combat, you must spend a full turn to complete the morph (this includes action, movement, bonus action, and reaction).  At 6th level, the time it takes to morph is reduced to an action. At 11th level, the time it takes to morph is reduced to a bonus action.

While morphed, the following rules apply:

• Your Strength, Dexterity, and Constitution ability scores are replaced by those of the creature you morphed into. Your saving throw proficiencies are also replaced.  You keep all your skill proficiencies that derive from Wisdom, Intelligence, and Charisma, but those of Strength and Dexterity are replaced by the creature’s.  If the creature morphed has legendary or lair actions, you can’t use them.
• When you morph, you keep your own Hit Dice, but your hit points become that of the creature’s. If you are reduced to 0 hit points while morphed, the normal unconscious and death saving throw rules apply.  You must be conscious to morph back into your normal form.  When you do morph back, you return to the same number of hit points you had before you morphed.
• You are unable to use your monk abilities while morphed. Speech and external interaction is limited to and determined by the creature you are morphed in to.  You are not able to attempt to attune to another creature while morphed.
• Armor will not morph with you, but weapons and equipment will if you so choose. If you choose not to have your equipment morph with you, it maintains its normal size regardless of the size of your morphed form.

You can remain in your morphed form for a number of hours equal to half of your constitution modifier (rounded down).  You can revert to your normal form earlier by using an action on your turn. If you do not revert before your time limit expires, you are trapped in the current morph and you no longer have access to your ki points or monk abilities. Only a wish spell or divine intervention can revert you to your old self.

Tele-Communications

Starting at 6 level, you are able to communicate telepathically while in your morphed form.  You have a range of 50 feet.  You can choose who in the range can hear you.  You are only able to speak in languages you know, and those hearing you can only understand if they know the language you are speaking. 

At 13 level, Tongue of the Sun and Moon and this feature can be used simultaneously.  Your telepathy will be understood by any creature who hears you and can understand a language.

Phenotypical Specialty

Starting at 11 level, you have become specially attuned to a certain type of creature. You can take advantage on Concentration checks when attempting to attune to a new creature without expending ki points.  Choose one type of creature from the following list: Beast, Fey, Humanoid.

Attunement Ease

Starting at 17 level, subtract 1 ki point for each attempted attunement for creature size.  For example, tiny and small creatures no longer add any to the DC, and gargantuan creatures now only add 4.

 In addition to this, you can now take advantage on attempted attunements while in combat.