(Slight DRK level 60-65 spoilers, some dialogue taken from the cutscenes and edited)
TLDR: How Ais found out about his real name, his origins, and the fate of his parents. Inconclusive ending but he would eventually recall memories of his childhood slowly!
This happens after the main events of Shadowbringers 5.0 as I’m following the order of how I picked up the Dark Knight class after 5.0, and there are no spoilers for MSQ, only some mentions of the outcome in Heavensward and the azim steppe in Stormblood.
"Wielder of dark arts! Consort of dragons! I will bring you to justice, even if it costs me my life!" The temple knight spat at him with such seething fury, Halone could have been proud.
"Shall we oblige him, then?"
A voice he'd never heard before. He turned to the direction of where it came from, and there stood a white-haired Xaela, clad in black armor and wielding a greatsword. Teal limbal rings of his eyes glowing through the slight fog. He took slow steps towards Ais and the knight, taking his time with confidence in his stride.
An Auri? An Auri just like him in the middle of Coerthas? That was all he could think of. Who cares about the knights who lured him out to kill him, that wasn't important. But to find an Auri? What are the odds here?
Ais had barely noticed when the knight ran for his life, even though he was the one who spared him.
"We who consort with the darkness are never truly whole. There will ever be a part of us yearning to be free."
He seemed to know Fray, surprised even, to find out that Ais knew him too. Ais shot him a questioning look, wondering if this guy was really out here in the snow to save him, or to end him just like the knights wanted to.
"There is a matter I would discuss with you, but not here."
A hint to follow him, then. He turns around and walks in the direction of Ishgard.
Sidurgu. The name felt familiar, as if the name had rolled off his tongue before. Sidurgu spoke of the Dark Knight's order, and presented Ais the sword of the knight who vowed to take his life shortly before.
"That's right. I followed him and gave him the 'mercy' he truly deserved!" Sidurgu spat, with his brilliant teal eyes burning into Ais' own. Ais studied the sword in an attempt to escape the gaze.
"The first Ishgardians to encounter Au Ra saw Dravanians. We had fled Garlemald's armies only to come to a land where we were mistaken for another nation's mortal enemy. They bared steel and came to kill us...but we did not die so easily."
"So tell me- Ais, was it? You, an Au Ri, a Xaela like me no less. An unconventional name. Where did you hail from? Were you aware of the Ishgardian's deeds?"
It was a lot to take in. A Xaela tribe that had fled to Coerthas... could this be a lead? Meeting another Xaela was dizzying enough, but this information was not what he'd expected today when he was lured out to be executed. 'The answers really come to you when you aren't searching for it', he thought to himself bitterly.
"I... have no recollection of my past. Ais was a name given to me by a fellow adventurer, nothing more than that. I woke up on a ship heading for Limsa Lominsa, and I have been looking for answers ever since," Ais looked away, staring at the dancing flame of the candle between them.
He looked up and subconsciously hugged himself, "I have met with our people in the East, yet I do not feel like I belong. I feel like I belong only in Ishgard, in Coerthas."