Way of the Blue Mage

The Order of the Blue Mages were founded after the great Chimera Rebellion, an occasion on which an Emperor's son was assassinated by rampaging Chimera. The Emperor then caught and confronted the alchemists responsible with making the Chimera, charging them with finding a means to defeat the creatures. The Alchemists, after many failed attempts, concluded that the Emperor's elite ascetic guard would have to become monsters themselves. At first, it was a disaster. Attempts to graft animal parts and limbs to humans resulted in gruesome and horrific outcomes when most of the test subjects' bodies rejected the grafts. Finally, the Alchemists found a brutal way to bind the essence of a monster directly to the human spirit. Thus, Blue Magic was born.

It came with a price, however: no known Blue Mage lived to the end of their natural lifespan. Also, using Blue Magic put enormous strain on the user, usually putting them through a great deal of pain. Another ghastly side effect of the process happens when the spirit of the beast bound to the Blue Mage's soul begins to corrupt their mind. In most cases, they begin to go mad with power, unable to control their new bestial urges. In rare cases, they lose all human emotions and qualities, and become Mind Flayers.

While they may be powerful warriors, it is only because they are no longer human.

Azure Lore

At 3rd level, the countless hours spent honing your ki into a malleable state, as well as training your mind's eye to quickly and accurately determine and memorize a creature's attack patterns after seeing them firsthand in combat, has bolstered the capacity of your martial arts. When you see a creature's special melee weapon attack, ranged spell attack, or spell-like ability in combat, you can spend 1 ki point and your reaction to roll an Insight check versus the creature's Armor Class, in an attempt to understand and memorize its function. If successful, you learn the attack or spell-like ability you've witnessed.

Once learned, an attack or spell-like ability is considered Lore and is only usable after you have finished a short or long rest. Lore are considered monk ki features that use an action and cost a number of ki points equal to the creature's Proficiency bonus. A Lore retains any recharge or per day restrictions it has, and the number of damage dice, damage dice size, and difficulty checks it contains, can never exceed the monk's current Martial Arts die step and Ki save DC. In the same instance, a Lore's maximum damage and difficulty checks are determined by the original creature. You can choose to forget Lore during a short or long rest, and the maximum number of Lore you can commit to memory is equal to your Proficiency Bonus.

You are unable to learn passive abilities, spells, weapon attacks, and legendary actions.

Unbridled Learning

By 6th level, endless study of creature anatomy and tactics has engraved their movements and behaviors into you on an instinctual level, leaving you better equipped in your dealings with them. You gain proficiency in the Arcana and Nature skills.

Monstrous Enchainment

At 11th level you have learned that by subtly weaving ki into your attacks, you are able to generate Lore nearly instantaneously. Immediately after taking the Attack action on your turn, you may spend ki points necessary to use a Lore as a bonus action. 

Astute Assimilation

When you reach 17th level, the knowledge and control of your mimicked abilities nears perfection.  You gain access to the following ki features:

Convergence

When you use a Lore that would affect multiple creatures, you can spend half the ki points(rounded up, minimum of 2) and choose to have it affect one creature within its range instead. 

Diffusion

When you use a Lore that would affect one creature, you can spend double the ki points to turn its range into a 15-foot cube originating from you.