I was reading the ECS section about the Overlords today since my campaign is focused on one of the bound evils. After reading it I found myself with some questions. I realize the answers to these is as aalways "Whatever you want", but I was interested in seeing what other people thought.
Are the Lords of Dust the Exarchs of the bound Overlords? Or are thos just the top of the heap?
Are all members of the Lords of Dust Rakshasas, or are there other creatures among them?
Does each Overlord have an Exarch? Do any have more than one?
I was reading the ECS section about the Overlords today since my campaign is focused on one of the bound evils. After reading it I found myself with some questions. I realize the answers to these is as aalways "Whatever you want", but I was interested in seeing what other people thought.
Were you reading the 4E ECG, or the 3E ECS? The 4E ECG has considerably more information. The subject is dealt with in even more detail in the (print) Dragon article "Eternal Evil". As always you can do whatever you want, but speaking to canon:
Are the Lords of Dust the Exarchs of the bound Overlords? Or are thos just the top of the heap?
Each of the bound Overlords has an exarch, also known as a prakhutu or "speaker". Most of the prakhutus are the prime agents of their Overlords, but there are a few who instead seek the power of the Overlord for their own; they are the most closely connected to the bound spirit but do not serve it. The prakhutus form the Council of Ashtakala, the body that seeks to prevent the agents of the different overlords from stepping on each others toes and mediates disputes when they do. However, "the Lords of Dust" as a term encompasses many more spirits and even mortal agents; the prakhutus are simply the forces at the top. It's worth noting that it's not a monolithic organization, and the prakhutu of the Voice in the Darkness has no authority over a pawn of the Keeper of Secrets, aside from the fact that you'd want to be nice to someone that powerful.
Are all members of the Lords of Dust Rakshasas, or are there other creatures among them?
There are other creatures among them. The "Eternal Evil" article listed five members of the Council of Ashtakala, of which one was a pit fiend and one was a succubus. The rakshasa are the most common fiends of Eberron, but not the only fiends. As noted in other sources and threads, there are Overlords that have nothing to do with rakshasa (Tiamat, the Heart of Winter, and those are just a few examples).
Does each Overlord have an Exarch? Do any have more than one?
Each Overlord has a prakhutu, a spirit closest to them that can hear their whispered voice. However, as noted above, this doesn't always mean that this prakhutu serves their interests. And some Overlords do have more than one representative on the Council of Ashtakala. In "Eternal Evil", the prakhutu of the Oathbreaker is the rakhsasa known as the Voice of Chaos, but the succubus assassin Thelestes is presented as one of his prime agents.
So that's the canon take. ;)
Are all members of the Lords of Dust Rakshasas, or are there other creatures among them?
Straight from the Eberron Campaign Guide
Chief among the fiends who escaped imprisonment were the rakshasas; they had close ties to Eberron and could not easily be pushed into Khyber. These and other demons drawn from Khyber serve their fearsome overlords, and are known as the Lords of Dust.
While some of the 4th ed fluff may be slightly incompatible with the 3.5e fluff (e.g. how large Khorvaire is), I don't know why this wouldn't be true for both editions.
[EDIT]: Ninja'd by Hellcow.
FYI, "Eternal Evil: The Lords of Dust" was in Dragon #337; it may still be available in PDF form on Paizo's website.
FYI, "Eternal Evil: The Lords of Dust" was in Dragon #337; it may still be available in PDF form on Paizo's website.
It appears to be, so thanks for suggesting that. I thought paizo had lost their license to sell PDFs of their issues of Dragon last year.
I might have to look through them one day and see which ones are worth buying for their fluffy goodness 
(although for now I've got quite a backlog on the D&D books I want to read!)
Thanks guys, I was reading 4e, but I guess some of it got glossed over in my reading.
I like to stick to cannon as much as I can, and only deviate where absolutely necessary, and most of this alows me to work with in cannon for my story, and what doesn't is easy enough to fix where it atleast works closer, and thanks for the article Keith, that will be helpful.