Soul Calibur II, I used Talim the most (by a long shot) and actually did pretty well with her. The only person I couldn't beat, ironically, was someone new to the game that used a Damascus-wielding Mitsurugi. Sure, they couldn't block, but you're down in like 3 or 4 hits. x)
Soul Calivur III - 100% Xianghua. She's by far my favourite. People say she's been "downgraded" from her godly tier spot in SCII (she was probably my 3rd favourite there), but to me, she's a much more fluid character that before, and probably of all of the other characters in the game. I don't know, she has a completely different feel to her. Now, a button-mashing fiend has no chance. =P
But, for the record, I HATED Nightmare in SCII with a fiery passion. Such a cheap character (not hard to dodge, but he hits for a godly amount with his two final weapons, especially the Soul Edge. x_x). Don't know, too many people used him for my taste.