Yi Minn is a Githyanki (WP), the half of the Gith that split from the Githzerai (WP) after Zerthimon's (WP) "two skies" pronouncement. As such, he and Dak'kon have only enough to say to each other to lead them into combat. Yi-Minn's death then leads to a large number of Githzerai Soldiers moving to attack.
If single combat between Dakkon and Yi-Minn is chosen, and no other party members make any hostile actions in in any way (trading Dakkon healing items does not seem to affect this), then the AI for the resulting flood of Githyanki Soldiers is confused, and they attack each other down to the last man (who can be dispatched or ignored)
This is not the only result that can be achieved, however; selecting party members other than Dakkon and then moving them to Yi-Minn's location, or removing him from the party altogether, leads to the entirely different, and in many ways preferable outcome, of learning the Githyankis' plans.
Yi-Minn offers to restore The Nameless One's memories, and lead him away alone. If TNO follows Yi-Minn alone, he is ambushed by the Soldiers, and can choose to either -Fight- them or -Let them kill- him. Choosing the latter leads to him spying on the Githyanki and hear of their upcoming raid on the Vristigor Githzerai base while dead. After they leave, he simply resurrects on the spot. It is probably nearly impossible to Fight any of the warriors and still have them kill TNO, assuming the trigger to resurrect is not disabled by choosing to Fight in any case, because of the warriors' preference for killing each other noted above.
Location: (L key) 2645, 980
A Gith woman, Kii'na, benefits from this information, which gives the party 8,000 XP. She moves from 800, 1800 to 1200, 1950 to 800, 2195. She then moves off the map and disappears.
The conversation with her incurs a great deal of the same enmity as the one with Yi-Minn if Dak'kon is in the party, but it is possible to navigate the conversation tree and still get her to mention Shrak'at'lor. TNO can ask Dakkon about this subject later, although he can be asked about it anytime after returning from Pharod and going to Fell's tattoo parlour. Dakkon reveals that he was a leader in this city and his word was relied upon by its inhabitants to reinforce the willpower required to keep it whole and functioning in the Limbo environment where the form of matter itself can only be held together by concentration. When Dakkon came to doubt the teachings of Zerthimon, his will faltered, and with it, the peoples will, and their city.
Qwinn's "Unfinished Business" mod's "Restored Lower Ward Encounters component" allows Ki'ina, with information about the results of the raid, to return to the Lower Ward after about a week of game time.