Any gifted soldier can have the first training at any point, but to train additional abilities they must be at LT rank or higher. Then, with each level up they can train ONCE at the Psi Lab to get one more Psi ability, for a total of 5 abilities at COL rank.
Because there are less psionic levels, each psi promotion grants the user 15±7 Psi Stat per promotion.

Focuses around single target attack and defense.
Starting Ability Soul Fire.
Other abilities:

• Corpore Sano (Psionic heal, 2 charges per mission)
  
• Null Ward - grants shields to the entire squad (like Shieldbearer)
  
• Manu Forti - grants damage buff to the target.
  
• Kinetic Push - knockbacks a target. Free action.

Focuses on environmental attacks and defense.
Starting Ability: Fortress.
Other abilities:

• Bastion - Fortress now extends to an AOE around the soldier (like Solace)
  
• Fire Whip - fire attack that also disables the weapon.
  
• Thunderous Roar - electric attack that puts the target's psionic abilities on cooldown.
  
• Boulder Crush - can stun the target.

Focuses on mental attack and defense.
Starting Ability: Unbreakable (immunity to mental effects)
Other abilities:

• Mens Sana - remove mental effects from an ally in range.
  
• Soul Merge - grants stat boosts and an action to an ally.
  
• Compulsion - mind controls an enemy: they get immediate actions, but the effect wears off at the start of the alien turn.
  
• Insanity

Focuses on manipulating the dead.
Starting Ability: Psi Reanimation
Other abilities:

• Restore Life - recovers bleeding out allies.
  
• Zombie Puppeteer - controls undead units (lost, zombies)
  
• Cremation - creates an explosion around an undead enemy.
  
• Halt Undead - stuns undead units.

Focuses on concealment and scouting.
Starting Ability: Battlespace (extends vision range, and grants an active ability to increase it even more for one turn)
Other abilities:

• Blend - enter concealment that expries in two turns.
  
• Wall Phasing - the ability from the Wraith Armor.
  
• Sixth Sense (Proficiency) - can reveal hidden enemies around the user without line of sight.
  
• Target Definition.

Focuses on manipulating space and time.
Starting Ability: Pillar (like Templar pillar).
Other abilities:

• Transposition - can swap position with an enemy or an ally.
  
• Stasis
  
• Sixth Sense (Shadow Ops) - immunity to area of effect attacks.
  
• Phase Walk - teleportation.

Focuses on interaction with equipment and technology.
Starting Ability: Fuse.
Other abilities:

• Circuit Breaker - deals guaranteed damage to a robotic enemy, and stuns it.
  
• Psyber Interface - increases aim vs robots and boosts hack stat.
  
• Unwavering - repairs shredded armor per turn.
  
• Barrier Charge - restores shield HP per turn.

Focuses on blood magic.
Starting Ability: Bloodied Shroud - increases HP and decreases wound recovery time.
Other abilities:

• Curse Breath - Cone AOE attack that costs HP and causes bloodcurse.
  
• Ruby Curtain - spend HP to grant an ally shields.
  
• Devouring Shadow - a version of Templar's void conduit, that costs HP.
  
• Flesh of my flesh - revive a bleeding out ally using your HP.