I've decided to make Arrgh available for any of the DMs to use, with the following caveats. You may not reveal any of Arrgh's past, that is all part of my own plots.

Background:
As you can see on the list of Ancient PCs Arrgh is extremely old. He is in fact older than any/most of the Lords of Orhan.
Arrgh was not born on Myaasia. He arrived on Myassia in it's youth and decided to stay, mostly because of the effect the abundant magic had on his abilities. Where others need to rely on technology and other such aids (like the navigators), Arrgh does not.
Arrgh does not have, and doesn't want to have a big impact on Myaasia. He loves Myaasia and will do what he can to protect it, but he will never interfere directly. The most he will do is give enigmatic comments to adventurers.
Arrgh is not scared of anything or anyone. Even the Gods (those that know of him) tend to avoid controntation with him if they can. As a result he tends to be very irrevent and carefree. He likes to call those dressed up in full plate “Tin cans”.
He's witty, insulting but generally good natured. He loves being fed, he likes egg and meat, but he doesn' eat sweets. (“Bad for my teeth, and how the hell is a rat supposed to hold a toothbrush?”). He plays on his nature as a rat to make points, and is unashamedly proud of both his appearance and its limitations.
Arrgh tends to suppress most of his memories. Players that want information from him will have to keep asking and badgering, but only when they are least expecting it (usually talking about something different, or when they mange to completly distract arrgh from the main point) will some memory of Arrghs surface and he mentions it as an asside, usually as if it were some unimportant fragment, and he promptly forgets about having mentioned it.
He lives in the sewers under Cerea and Carse, but generally if there's a sewer somewhere, he'll have been there.
The powers he has currently revealed to players are: The ability to instantly transport himself and others (“Damn you guys are heavy!”) to any location, regardless of essence streams or other barriers. He very rarely takes other people though, and tends to use this ability for quick visits to other cities' sewers (“for lunch”).
His other power is the ability to kill anyone instantly (In DM terms, cast a finger of death and then kill the player using the DM console). He tends to only do this to those that insist on attacking him (kicking included). He will never raise someone he kills like that.
He also has the ability to hold someone totally immobile, like a hold monster/hold person spell, and he prefers to use that for those that irritate him (you'll need the players' cooperation on this for the most part).
Arrgh has been near most significant events in Myaasian history. If the records existed and people paid attention some might have wondered why a rat was watching the most significant events in Myaasian history.
The Rat is not his actual shape, and he can assume any guise he wants. For DM's the ability to appear as something other than a rat is for my use only, as it is closely linked to various plots.