Qara vs. Ignus

First of all let's get this out of the way: Ignus would liek, toe-tuh-lee kick Qara's ass.

But anyway. Pyromania has become a bit of a spellcaster trope. It's an easy, flashy display of fantasy special effects. Even the dumbest gamers can grasp the idea of shooting fireballs as "magic power" so it's hardly surprising in retrospect that Neverwinter Nights 2 included something like Qara in its panoply of DnD archetypes. For those who have also played the NWN predecessor Planescape:Torment a comparison with that other firebug companion, Ignus, seems natural and at first glance Ignus appears by far the better-written character.

I don't think Qara was particularly popular a decade ago when NWN2 came out. At least in the online game guild I was a part of at the time, I found myself her only advocate. Others complained of her abrasive personality or skill build as grating flaws. She was accused of being precisely the sort of "munchkin" who plays a sorceror - a charisma-based character with the diplomatic skills of a poop-flinging baboon who only wants to deal damage but for whom weapon feats were just too complex.
For this reason Qara really is a good character. She embodies that archetype. She may be a bad person... but a decent character nonetheless. Personally I liked having her around because it's nice having some NPC in these games that's a bit of a loose cannon. She provided some nice accompaniment for the explosive side of my own temperament much as Gannayev or Morrigan echoed my egomania and callousness in later Bioware releases.
One must also keep in mind that "charisma" is not synonymous with "niceness" and abrasive but magnetic personalities abound. Consider comedians, for instance.
Her somewhat repetitive dialogue also fits. Pyromania aside, the monomania of obsessively pursuing anything - power especially, magical or otherwise - can easily become the focus of one's entire personality. Qara is gradually becoming her conflict, constantly manifesting her fight to break free of the restraints placed upon her. 

However, there is an added dimension to Qara for those players who have gone through both Torment and NWN2. Ignus is by far the more captivating character, granted. His interactions with the player, his viciousness and abandon make Qara look like the G-rated imitation she truly was. However, when looking back at Qara one must realize that what we were presented, in part, was another Ignus in the making. Qara is Ignus the child, Ignus the hedge-wizard who burns with the art... until the art will inevitably burn her. There's even an easy comparison to be drawn between Qara setting a fire as a diversion in a backalley of Neverwinter's docks and Ignus torching the Alley of Dangerous Angles.

Qara was an interesting character because she was a transitional one, and in a much subtler way than Khelgar. She was in that state of potentiality awaiting some apotheosis like, say... being turned into a conduit for the Plane of Fire. Unfortunately, fully exploring that path would have been too deep for NWN2's simplistic, archetypal companion roster. Ignus she could've been, munchkin she remained.