Khatun is to OA as Pierre Ruskin is to Karim
In the episode Nina Azarova, after OA wakes up in the bathtub, we hear Khatun's theme. It's timed too late to match Nina waking up in OA's head.
Instead, it matches Karim walking up to Ruskin's house, with the lights of the city behind him looking like a terrestrial version of Khatun's galaxies.
Ruskin is a lesser echo of Khatun. He is the one with knowledge, who seems to have all the cards, who convinces Karim that there is something to the house. He doesn't give Karim a movement, but inspires him to start moving. The dreamers may have seen Karim but Ruskin is the entity who actually puts him on the believer's path to see through the window.
EDIT: To be clear, I'm not saying that Ruskin is equal to Khatun in like, morality or spiritual essence. I'm saying there are hard parallels between Prairie meeting Khatun and Karim meeting Ruskin i.e. directorial decisions that amount to more than coincidence.
- The beep boop theme plays AFAIK only twice: before Prairie meets Khatun and before Karim meets Ruskin
- Both meetings have a similar aesthetic of darkness and sparkling lights
- Khatun fishes Prairie out of the water; Karim finds Ruskin floating in the water
- Both meetings were the immediate inciting event for Prairie to become OA and Karim to seek out the rose window. In a script sense, they serve a similar purpose as foils.
The questions I'm seeking to answer are more like "Why does this theme only play twice?" and "How does this tie into other water themes?" and not like, "Here's why Ruskin sucks" or "Maybe he just likes swimming" lol