You sit in a circle surrounded by other circles containing a certain set of random objects. You aren't supposed to be wearing anything, so it's often done privately, but more importantly I don't know how that interacts with you not being technically an incarnate. Some of the random objects are food offerings; those disappear. Others move in front of you and you say what they make you think of, then you make a personal statement and the pledge of truthfulness. It's about letting the spirits know who you are, and then from then on they start paying attention to you.

A lot of the ritual is in a dead language. I have a translation into mine, and if you like I can send it over osanwe ahead of time as well as during.

I could do it while not in incarnate form, depending what's important about being unclothed.

I think it's about— not having any barriers between you and the world you're joining. Pretty much everything involved is symbolism one way or another. 

That and the fact that the entire ritual works by tradition, but aside from the concept of dead languages the fact that she's from a different world has yet to be relevant.

I will do it without incarnate form, then, I think. 

All right. We have some of the materials, but you'll need a rose, food and alcohol of any kind, a dagger... she ends the list with "and preferably soundproofing."

I will have someone bring them.

In the meantime, ritual translation? The dual columns of English and who knows what would be doubly useless, but if Melian's signing onto the practice on the advice of imperfectly trustworthy people she might want to check that the text matches the summary.

Please do tell it now.

It is pretty much as described. A few references without referents, talking about the ways things are done, but those she can clarify refer to the karma rules.

And she concentrates intently and then says smoothly, not from her body, which has stopped moving, all right. I will conduct the ritual here. Elu -

He moves towards where the voice is coming from.

Um, nearby is fine if you've told him about the practice, but you shouldn't have two people in the circle....

But I need to have the thing that is important to me with me, yes?

She stifles a laugh and then realizes that no, this is the opposite of funny.

I don't think there's a rule saying the personal, object, can't be a person. Never heard of it being done.

But it shouldn't have any unfortunate implications for this purpose at least, so In one of the six circles in the middle ring.

This is arranged.

And as she starts receiving syllables to repeat, everything not in the diagrams fades into unimportance. The components start shifting position and some of them appear one at a time in front of the space where Melian's body isn't. At each of those points the script stops while Melian says anywhere from a word to a paragraph about what she associates with the object. (Elwe is the last of these.) It ends with the bit that translates as a pledge that yep, no lies from here on out.

Afterward, the world looks the same as before but with another dimension overlaid on top of it. The other practitioners and their magic items stand out, but Melian is in Doriath and the rest of everything doesn't become less visible for it.

This is fascinating. Thank you. And the ritual to make Doriath safer?

That one's a lot more freeform and simpler.
Can you speak with one voice from each corner of where you want your demesne to be? An incarnate who wanted to claim a large area would have to be really loud, but you might be able to skip that.

I can do that. Now?

It can be. The challengers—you won't get any from in here since that's already yours, but there might be something nearby... if the trees and things outside your realm had opinions about you holding Doriath would they be favorable ones?

The spiders and the Valley of Dreadful Death might object.

Valley of—okay.

So if there are any Others there intelligent enough to respond they might show up and contest your claim. But you get input on what the contest is, even if they get first pick of a detail, so it can just be something that lets you toss them out and declare victory.

Very well.

Could I have my demesne be all of Doriath except Menegroth, and then have Elu or my daughter claim Menegroth? To avoid the problem with becoming lost to the world?

That might help. Or it might not; there'd be no more links to the outside than if both were yours. Both could just fade as a unit.

The main problem is that I don't think anyone else could claim Menegroth. Doriath is your place in a very complete sense, and that's also how demesnes work, so you'd have to first give up all personal claim on the part you set aside.

Hmmm. No, that wouldn't work.

I thought it might not.

The limit on how far it can extend, aside from what you can take and what you can hold, since neither of those will pose a problem for you, is whether your voice reaches the edges. Do you have whatever you need set up so you can speak from everywhere on the border?