Why the name BitterSweet?
The first name of the Guild was Dark Misstress. The name just didn't match Karin at all. Now that Karin has red hair, I had to try to find something to related to that. Not only relate to her hair, but her personality as well. Bittersweet has many different meanings.It's a type of plant,color,emotion, and even chocolate. The Bittersweet plant is red,and the Bittersweet color is reddish-orange. It just fits so perfectly with her hair. Now with her personality wise. Karin can be bitter one minute, and sweet the next. BitterSweet kind of emphasizes Karin's split-personalities.

bit·ter·sweet (bĭt'ər-swēt')
n.
A woody vine of the genus Celastrus, especially the North American species C. scandens and the eastern Asian species C. orbiculata, having small, round, yellow-orange fruits that open at maturity to expose red seeds. Also called staff tree.
See bittersweet nightshade.
A dark to deep reddish orange.
adj.
Bitter and sweet at the same time: bittersweet chocolate.
Producing or expressing a mixture of pain and pleasure: a movie with a bittersweet ending.
Dark to deep reddish-orange.
Link: http://www.answers.com/bittersweet&r=67