This mod ports the forgotten Mystic class from Unearthed Arcana into Baldur's Gate 3, along with all subclasses, psionic talents and most psionic disciplines!
Some spells and features had to undergo reworks or changes due to the way they work, though I tried to keep reworks and changes to a minimum.

Requirements

• Script Extender
• ImprovedUI is REQUIRED, otherwise you won't be able to see all the Psionic Disciplines
• ImprovedUI Assets is also needed to see class and resource icons
• Compatibility Framework, for Extra Feats, Double Resources and Godmode
• Shivero's VFX Library and Vlad's Grimoire
• Object Character Support
• Additional Fighting Styles
  
  

The Mystic
Mystic is a purely psionics-based class, and they use a unique resource called Psi Points. Each "spell" has a Psi Point cost, and the amount of Psi Points you can spend at once depends on your Mystic level, this is known as your Psi Limit. You start with a few Psi Points, and the amount you get increases with each level. Most spells have a static cost, but some allow you to "upcast", increasing in power for each additional point spent. The maximum cost for any spell is 7 Psi Points.
The amount of Psi Points you can spend at Level 1 is 2, increasing to 3 at 3rd level, 5 at 5th level, 6 at 7th level and 7 at 9th level.

Psionic Talents
These are functionally your "cantrips", they are essentially free to use, and don't cost any Psi Points. They also have similar power to cantrips or regular weapon attacks.
You learn 2 psionic talents at level 1, plus an additional one at 3rd and 10th level.

Psionic Disciplines
The bread and butter of this class. There are a whopping 38 psionic disciplines to choose from, each with their own theme and mechanics.
You can choose any psionic discipline at 1st, 3rd, 5th, 7th, 9th, and 12th level.

Class Features
Choose a subclass at Level 1. Each subclass can choose an additional 2 psionic disciplines specific to their order, with the exception of Soul Knife.
[Level 2]
Telepathy: Allows you to read minds. Basically Detect Thoughts.
Mystical Recovery: After spending Psi Points, you can use a bonus action to regain hit points equal to 1 + your Mystic level.

[Level 4]
Strength of Mind: Permanently gain Proficiency in a Saving Throw of your choice. You can change this once per short rest. Upon learning this you lose your Proficiency in Wisdom Saving Throws (you can get it back though, if you so choose)

[Level 8]
Psionic Strike: After dealing weapon damage, you can deal an additional 1d8 psychic damage. Works similar to Divine Strike from Cleric.
At 14th level, the damage is increased to 2d8.

[Level 10]
Consumptive Power: Sacrifice 14 maximum hit points to regain 7 Psi Points. Once per Long Rest.

[Level 11]
Psionic Mastery: Once per turn, spend a Psionic Mastery charge to cast a spell for free and without consuming an action or bonus action.
Gain a Psionic Mastery charge at 11th, 13th, 15th and 17th level.

[Level 20]
Psionic Body: Gain resistance to Physical and Poison damage, as well as immunity to disease and the poisoned condition.

Subclasses and Features
Order of the Avatar
- Able to manipulate emotions, supporting allies and crippling foes
[Level 1]
Armour Training: Gain Proficiency with medium armour and shields.

[Level 3]
Avatar of Battle: Permanent aura. Allies within 9m gain +1 to Initiative.

[Level 6]
Avatar of Healing: Permanent aura. Allies within 9m regain 2 additional hit points from all sources of healing.

[Level 14]
Avatar of Speed: Permanent aura. Allies within 9m can use Dash as a bonus action.

Order of the Awakened
- Masters of the mind, delivering high damage and control
[Level 1]
Awakened Talent: Choose an additional skill from the following list: Animal Handling, Deception, Insight, Intimidation, Investigation, Perception, and Persuasion.

[Level 3]
Psionic Investigation: Gain Advantage on Investigation, Insight and History Checks. Once per Short Rest.

[Level 6]
Psionic Surge: As a reaction, you can impose Disadvantage on a creature when you force it to make a Saving Throw. Once eper Short Rest.

[Level 14]
Spectral Form: As an action, take the form of a spectre, becoming immune to damage and halving your movement until your next turn. Once per Long Rest.

Order of the Immortal
- Use psionics to fortify and alter their bodies
[Level 1]
Immortal Durability: Add your Constitution modifier to your Armour Class. Increases your hit points by an amount equal to your Mystic level.

[Level 3]
Psionic Resilience: Each turn, gain temporary hit points equal to your Intelligence modifier.

[Level 6]
Surge of Health: As a reaction, halve incoming damage. Once per Short Rest.

[Level 14]
Immortal Will: Toggleable passive. At the start of your turn, if you are downed, spend 5 Psi Points to regain hit points equal to your Mystic level + your Constitution modifier. Can only trigger once per Long Rest.

Order of the Nomad
- Fantastic mobility and good with ranged weapons and non-combat utility
[Level 1]
Breadth of Knowledge: Gain a +1 bonus to all skills.

[Level 3]
Memory of One Thousand Steps: As a reaction, force an attack to miss you. On your next turn, you can teleport up to 9m for free. Once per Short Rest.

[Level 6]
Superior Teleportation: Increase the teleportation range of psionic disciplines by 3m.

[Level 14]
Effortless Journey: Once per turn, teleport up to 9m. Costs 1.5m of movement for every 3m travelled.

Order of the Soul Knife
- Able to create a pair of soul knives to strike foes
[Level 1]
Soul Knife: Manifest a pair of soul knives. They scale with your Intelligence instead of Dexterity and deal 1d8 psychic damage.

[Level 3]
Hone the Blade: Spend Psi Points to augment your Soul Knives. You can spend up to 7 Psi Points for a +4 enchantment.

[Level 6]
Consumptive Knife: Whenever you reduce an enemy to 0 hit points, regain 2 Psi Points.

[Level 14]
Phantom Knife: Perform a regular weapon attack that cannot miss.

Order of the Wu Jen
- Elementalists that harness and control magic with their minds
[Level 1]
Hermit's Study: Choose an additional skill from the following list: Animal Handling, Arcana, History, Insight, Medicine, Nature, Perception, Religion, or Survival.

[Level 3]
Elemental Attunement: As a free action, spend 1 Psi Point to choose an element and ignore creatures' resistance to it when dealing damage. Once per turn.

[Level 6]
Arcane Dabbler: Learn three Wizard spells. As a bonus action, you can spend Psi Points to get spell slots (similar to Sorcerer).

[Level 14]
Elemental Mastery: As a reaction, spend 2 Psi Points to become immune to an incoming type of damage if you are resistant to it.

Mystic Gear
This mod also includes custom gear made for Mystics, which can be found throughout the game or in the tutorial chest. There is at least 1 piece for every slot, 3 tiers of melee and ranged weapons and a specific piece for each of the subclasses. They can be found in the following vendors:
Act 1 - Arron in the Druid's Grove
Act 2 - Quartermaster Talli in Last Light Inn
Act 3 - Entharl Danthelon in Wyrm's Crossing

Optional Files
Double Resources - Uses CF, gives double Psi Points and Psionic Mastery each level
Mystic Gear in Tutorial Chest: Simply adds all Mystic gear to the tutorial chest
Godmode - Uses CF, gives basically unlimited resources and unlocks the Psi Limit
Mystic Expansion - Adds miscellaneous homebrew options (don't expect regular updates)

Recommended mods
5e spells
CF Extra Feats
Unlock Level Curve
Tutorial Chest Summoning

Known Issues

• Some people seem to be experiencing crashes, putting the mod lower or last in the load order seems to mostly fix the issue
• Make sure you have ImprovedUI installed, otherwise you won't be able to see all the psionic disciplines
  

Installation
Use BG3 Mod Manager
Make sure ImprovedUI, 5e spells and Extra Attack Compatibility are above this mod in the load order.

Multiplayer
This mod should be compatible with multiplayer, just make sure everyone has the exact same mods and load order.