Riti

Riti is one of the souls imprisoned within the drow "Soul Trap Device" (or "crystal") in the Underdark during Baldur's Gate II Chapter 5. 
==Gameplay==
This creature can be released by manipulating the third facet on the device (from west to east or left to right - if facing the device).
When the facet is manipulated, a few moments later a teleport animation will initiate and place the githyanki nearby the party. 
Riti will initiate spoken dialogue. Regardless of the party's reply - hostilities will ensue.
Riti is scripted to just behave as a sword wielding melee attacker. He uses no Psionic Ability or spell casting. He won't offer much challenge.
Once defeated, the player's journal will update as follows:
:"Victims of imprisonment: I freed a githyanki from a strange crystal I found, but it barely bothered with a few words before attacking. It seemed to want to make up for being imprisoned by battling whomever it could find. If there're any more creatures in this crystal, I hope they are more reasonable."
A few items of dubious and potential good use can be found on the aggressive, but now terminated githyanki warrior.
==Note==
Riti is non proficient as a Fighter class with his Two-handed Sword. He'll have a penalty to hit. Developers did give him 3 pips in Spear weapons, but that's in his inventory, and not equipped.
==Mod content==
Installation of the Sword Coast Stratagems Mod makes a few changes to this githyanki. First, he is a Level 11/9 Fighter Mage. He has a full arcane spell book of memorized spells commensurate with a level 9 experience. Two spell sequencers are prepared. As an SCS gthyanki, he also has innate psionic abilities, including Psionic Maze and Planar Travel. He gets an SCS default script for better targeting, defense and tactical behavior, and an SCS "Smarter Mages" script.
Two pips in Two-handed sword weapon proficiency are assigned and two pips in Two-handed weapon style. SCS also adds random treasures to his inventory, probably an IWD spell scroll if you have that component installed.
His opening defensive (cast previously) buffs include Mirror Image, Haste, Minor Globe of Invulnerability, Shield (spell), Protection From Normal Missiles, Ghost Armor, Stoneskin, and Non-Detection. After that, he'll most likely attempt some offensive spells at the party and engage anyone close enough in melee combat.