There is a dialogue with either the Guardian or the meeting with Voss where you are told that the 'Ascended' are used to fuel Vlaakith's power.
I agree that the entire scene is mess.
On one of the earlier points: there is a scene long before the creche where Lae'zel sees the artefact and recognises the markings as githyanki. Might be the scene where the artefact saves you from the oppressive/dominating presence with the image of the three.
I opened a thread about the creche nonsense
https://forums.larian.com/ubbthreads.php?ubb=showflat&Number=886526#Post886526
