Thessaly

Thessaly was indeed a witch in The Sandman graphic novels by Neil Gaiman. Despite her youthful appearance, she was quite old, having made shadowy bargains to extend her lifetime by several thousand years. In her appearances in the series, she performed several interesting rituals, usually involving blood, if not actual sacrifice. She was pragmatic, self-protective, and quite humourless.

However, she played several key roles in the story arc of The Sandman, first as Morpheus' lover, in a disastrous affair that was probably a bad dating choice for both of them; and later she was pivotal in his ultimate fate.

She claimed she didn't love him, but she was crying as she said it.

Thessaly's name is taken from her very own coven. The thessaly were a ancient moon-worshipping cult of priestesses/witches who were said to work magic by "drawing down the moon." By using the moon's powers they could "stop rivers in their courses, turn back the wheel of the stars, or bring trees marching downhill." Another important aspect of this ritual was the use of menstrual blood, or "moon dew."

Neil Gaiman includes such a ritual in The Sandman story "A Game of You," and also manages to poke fun at the Wiccan or Neo-Pagan adoption of such practices:

Foxglove: "We did this. or something like this. We had water and salt, not blood. and white candles. We invoked the goddess in her aspect as the moon. We called down her power..."

Thessaly: "Did she answer you?"

Foxglove: "Well, it felt good at the time. Empowering."

Thessaly: "Hmph."

from http://tylwythteg.com/bos039234/bos07.html and, of course, A Game of You