The Aardi monks are set well apart from the average monk. Only a soul who has faced devastating personal loss can hope to withstand the ordeal of the mind it takes to become an Astral mind. When a monk chooses this path, they enter a state of meditation for several hours, underneath a starlit sky on the night of a full moon. When one emerges from this state, they are changed. They have formed a Mind-Link to the Astral Plane, overloading their being with the vast Wisdom of the stars. 
Monks such as this often decide to live in silent contemplation, pondering on questions about life, the universe, and everything. But if forced to fight, Aardi Monks can use their psyche to blast other's intelligence, dominate their consciousness and even paralyze their mind and body.

 

Enlightened Being

When you choose this archetype at 3rd level, you unlock the Wisdom of the Astral Plane. Your Wisdom score increases by 1, as does your maximum for that score. Your Wisdom score and Wisdom maximum increase by 1 again at 6th level.

 

 

Scathing Thoughts

Also at 3rd level, you gain the ability to send mind- piercing psyche to sear your opponent's intellect. 

When a creature within 30 feet of you makes an attack roll or ability check, you can use your reaction to blast that creature's mind. Roll a die, and subtract the total from that attack roll or ability check. This die equals your Martial Arts Die. You can use this ability after the d20 is rolled, but not after the DM announces the total of that attack roll or ability check.          

You can use this feature twice at 3rd  level, three times at 6th level, four times at 11th level and five times at 17th level.

 

Psychic Stun

At 6th level, you can emit psychic ripples that stun mind and body.

When you attempt a "Stunning Strike", you can choose for the necessary save to be Intelligence, instead of Constitution, to resist this effect.

 

Dominate Mind

Also at 6th level, you can use your action to try and dominate a creature's thoughts.

You can send and action and 2 Ki points to choose one creature within 60 feet of you. That creature must make a Wisdom saving throw against your Ki Save DC, or be put under the effects of the Suggestion spell. You may spend 4 Ki points to give that creature disadvantage on the save.

At 11th level, you can choose to effect any number of creatures up to your Wisdom Modifier within 60 feet of you to be affected by Dominate Mind. Expend the necessary Ki points for each.

Mental Undercut

At 11th level, when you hit a creature with a weapon attack, you may spend 1 ki point to give that creature a penalty to the first saving throw it makes against your "Stunning Strike" this turn. That penalty equals your Martial Arts Die.

Awakened Avatar

At 17th level, you become the embodiment of mental power. You may spend the following Ki points to cast the following Spells:

5 Ki points to cast Commune, asking questions to the sentience of the Astral Plane.

2 Ki points to cast Detect thoughts.

5 ki points to cast Synaptic Static.

The necessary saving throw against these spells go against you Ki Save DC.

Also, you can't be Charmed, and you have advantage on all Insight checks.