Sulatar Drow Assassin

[Afgncaap5]

I'm working on making the boss for the end of a short Eberron story where the players were hired by a professor from Morgrave to get something called The Fire of Ambition (also called The Torch of Initiative or The Spark of Progress) from a hidden Fire Giant ruin, located in a cave beneath a massive glacier in Xen'Drik that acts as a planar manifest zone to both Risia (plane of ice) and Fernia (sea of fire). I've introduced a Sulatar Drow to the story who reveres the Promise Of Fire, and doesn't want to see the Torch of Ambition (or whatever you want to call it) fall into the hands of those who don't revere fire and the fire giants as she does.

The players are level three-ish, and I want the Sulatar to give them a fight, though her primary goal is escaping with the Torch rather than killing all the players. Since she's a boss fight and not actively trying for death unless it's the most expedient option, I've bumped her up to being a Rogue 5/Assassin 3 (and since there are four to seven players, some of whom are pretty seasoned, the action economy is definitely on the player's side, meaning I'm going to want to improve her stats and gear to make it "tough but fair.")

So... any thoughts on how to properly outfit a fire-worshiping Drow assassin? Right now I've got the Smoke Stairs spell from Complete Scoundrel and the Burning armor quality for her armor since both are fire themed and appropriate to survivability and assassin-style work, even if Burning's more expensive than most loot I'm giving to NPC villains at this level. And is CR 9 just too much for an NPC to have against six-ish level three players?

Part of me wants to rebuild the Assassin using Spheres of Power as a medium-level caster with a focus on the Destruction (Fire), Dark, and Death spheres (and maybe just a pinch of Nature (Fire) as well...), but that feels like a lot of work for what'll probably just be one encounter.

[ExLibrisMortis]

There's the smoking weapon enchantment, which grants concealment.

A level in dragonfire adept can get you an all-day fiery breath weapon, which can easily be refluffed as something else if needed, and an invocation, such as scalding gust (instantaneous gust of wind +1 fire damage/CL - technically, it's permanent, because the invocation changes the duration).

[Afgncaap5]

There's the smoking weapon enchantment, which grants concealment.

A level in dragonfire adept can get you an all-day fiery breath weapon, which can easily be refluffed as something else if needed, and an invocation, such as scalding gust (instantaneous gust of wind +1 fire damage/CL - technically, it's permanent, because the invocation changes the duration).

I like the thought. I might use the fiery breath weapon for another member of her clan (fire binders likely have lots of different ways of manifesting their power, after all), and I think smoking is just about right. Is that the Magic Item Compendium?

[ExLibrisMortis]

Is that the Magic Item Compendium?
Nope, that's in Lords of Darkness, a Faerûn book.