Actually... This might make a good time to start introducing the "Pact arc" I have planned for Kyvir...
@Spirit, I'm assuming all the classic DnD pact options are available; The Archfey, Fiends, and Great Old Ones, right?
It's a solid assumption, but unfortunately this is gonna be kinda complicated due to lore. Basically you're never going to fully see anything more like glimpses of shadows separated by a force you can't fully understand. Demons don't actually come to this world, which I'm sure you're gonna get confused as to how that's the case when you're literally playing a tiefling. And the answer to that my friend is simple, you ain't gonna know about
that until someone looks into it in detail. So here's the thing, I never had anyone talk about pact magic and I kinda just assumed how it worked. For you though I'll do some good old fashioned dm handwaving. But with some conditions.
I'm not letting you do this straight out, as forming a pact with anything in this world requires you to actually
be in it's presence. So it's gonna be a bit complicated if you want a demon. First off, you're gonna have to contact a demon, or get to the infernal world. One of these is easier than the other, I'm sure you can figure out which one. lol
Once you do that, basic demon soul pact.
Option 2, Archfey. Another problem similar to demons, while there are normal fey on this plane, there aren't any Archfey on this plane. And getting from one plane to another is... Actually unprecedented. Possible, but not practical. There are a few way to do it, but going through all that effort in a RP is kinda out of your range of instant gratification. Table top, doing it is easier. But in the rp you're full immersion so this would take months of dedication to pull off in real time. You would have to study hard and put pieces of puzzles together, then once you figured it out you have to go on a few quests. And ain't nobody got time for that. Not to mention once you
get to that plane, you can't come back the way you came so... Yeah more than a few issues here.
There are a few other options that you have that there will be touches of in this rp as one character Isabelle already has had my explicit hand in tying her dissent into madness into a concept. And if you explore THAT particular area then you don't have to find ways to get a demon.
The last one though, creation mythos is kinda a bitch. Unfortunately the closest thing to the Elder Things in my lore is the most difficult thing to contact, and if you did you're going insane. Like no leeway on that you would be ripping out your eyes and smelling the colors of a butterfly's fart in a parallel world that is then also on the other side of that world. Seeing things you don't want to, experiencing pain in places on your body that don't exist, living lives within seconds of moments between real moments of your life, etc. And nothing can stop that once it starts. Soooo... Don't even try that lol
So if I had to give you more feasible options off the top of my head, finding a "living god" of an evil alignment, finding a powerful lich, or travelling to the far east and making a pact with a zodiac vessel would be the easiest ways of doing this. Or you know giving a catalyst of contact to an abyssal realm demon for a brief moment. All of these are highly forbidden except the Zodiac Vessels mind you, so caution.
Yeah having an expansive lore like this is meant to be explored from the ground up, hence why I like to be consulted like this.
But on the other hand, since I'm sure nobody has the patience to actually follow the lore to a T, we could just say fuck it and let you summon a demon with less of an issue. As long as you understand that
Oh quick afterthought, you do this out in the open and you're gonna be put to death like immediately soooo. Oh and there's always the option of binding to a less powerful familiar. Like a mermaid. Or a Dryad. Or a stick you're pretty sure is a dryad secretly that's too shy to tell you it's actually a dryad.