Mmm, well, charisma isn't just about looks, to me it's mostly personality. Sika is a borderline unstable half-demon lady, not to mention selfish, manipulative and vindictive since she acts on her impulses most of the time. She's more of a lone wolf than a people person due to her largely unpleasant experiences with society (this point is supposed to represent the -2 to charisma that Tieflings get), so she's bitter and mad at the world, a bit like an angsty teenager. To top it all off, she's learned that she can usually get whatever she wants out of people through threats and deception (she does worship the goddess of deception, after all), so why bother forcing herself to be nice with a world that has never shown her any kindness? (I modified her personality a bit from the initial concept to better reflect her profile)]<br/><br/>From a more practical standpoint, I just felt that reducing any of the other stats wouldn't work or that it would cause other issues. Str/Con/Wis are pretty much vital for the class if you want to be playing melee as far as I can tell, and I didn't think that it would be fitting for a spellcaster to have below average intelligence or for a lithe, young, warrior girl to be completely undexterous. A low charisma seemed like the easiest one to explain, especially considering that Tieflings start off with a charisma penalty.<br/><br/>Hope that makes a bit more sense.