If Sheila were to describe herself, she might say that she is a woman who is independent, strong-willed, and doesn't tolerate people who bother her or cause trouble. Given that she is described as a "tsundere," she may also come across as cold or prickly at first, but eventually shows a softer, more caring side to those she trusts. Regarding her feelings towards Xander, she might describe him as someone who enjoys violence and xauses too much trouble, until she knew her actual feelings...