I think what you’re asking is:
Was it an accident or kismet that Lestat found Louis randomly in a tavern in a sketchy neighborhood in NOLA?
Lestat went there for normal reasons: hunting evildoers as per usual, but it was NOLA bc he was looking for a fresh start in the New World. And Louis was there for also fairly normal – if not kind of upsetting – reasons, too: looking for someone to put him out of his misery, basically.
I would say it was kismet: Lestat was created for Louis, he was originally intended to serve as Louis’ maker, since we are introduced to him that way in the first book. Even Anne Rice didn’t anticipate that Lestat would essentially take the driver’s seat and create the rest of the series.
But it’s important to remember that, because he wouldn’t exist at all without Louis, in the fictional sense, and I think that’s part of what makes him so loyal to Louis in an ongoing way throughout the series. Louis’ rebelliousness as a fledgling and then the precarious but loving peace they shared for decades sets Lestat up for the pining for him forever after, and it’s only recently in the series that it feels like they are explicitly more in mutual love and awe of eachother than ever before.
If we look at it from Lestat’s perspective, which begins before Louis’ story chronologically, that relationship was a huge turning point for him. He lived out that lifetime that Marius told him to do, and for the most part, it was very good for all of them as long as it lasted. Lestat was the provider again, but this time, it was for a family who actually loved him, who he could love back ❤

^[Commission for me by the amazingly talented @ashetray]
^So of course I really love this fanart bc I COMMISSIONED IT, I asked for this composition, w/ Lestat in between Louis and his “dinner.” It’s actually based on an iconic moment in Dirty Dancing but anyway… Lestat had alot to teach Louis, and at least in this moment, he was saying, “I’ll bear the moral burden of killing tonight, it’s more important that you get what you need, so you can take it from me… rather than have /junk food/… but we’re not doing this EVERY night…” Also, he likes it when it’s HIS bodice being ripped open by Louis, for a change of pace!
They’ve also been through alot of canon events, terrible betrayals of eachother, generous forgiveness… so much feels. Which is why I can’t throw out entire books, there’s something worth saving in even the most difficult books to accept.
They say that your relationship with someone is established within the first 5 minutes of being with them, and I think those mutual feelings of friction and awe and attraction between them, added to the decades they shared as murder dads, and the other canon things they’ve survived, it’s all added up to keep them tied together, inexplicably. I think they’ve encouraged each other to be better versions of themselves, for the most part.
Hit the jump for moar thoughts.
In the universe of the books themselves, to elaborate a little: both Louis and Lestat were in a bad place when they found eachother. Lestat had a pretty rough first decade as a vampire, had already made and lost two fledglings. He lost them for different reasons but it still had to hurt. He had successfully gotten kicked out of Marius’ house for his usual bad behavior. Paris was no longer that great of a place for him. He had his blind old dad to deal with.
Louis was almost worse off, a lifetime spent as the man of the house, vigorously trying to kill himself by drinking all night and picking fights w/ whoever would fight him, feeling like a huge failure in the eyes of his family for the death of his younger brother.
So when they met and fell for eachother, it was intense, because they filled a void for eachother. Lestat wanted that companion that he thought Louis could be if he worked the magic on him, and Louis was overwhelmed by the attention of this supernatural creature, not just that he was a vampire (which would have been enough on its own!) but that he was LESTAT, with all that bravado and charm.
Add to that that they were both pretty awful to eachother, too, the friction actually adding to their mutual attraction in a way; Louis felt that vampiring was a great way to damn himself (tho he does admit he appreciated the heightened senses), and Lestat had found someone to question his authority ALL THE DAMN TIME.
It’s a very good ship from all angles, as dysfunctional as they both are.