Copypasta, since I lack any newbies. Woe:

atreideslioness

"Behold me, family," Leto said. "I am Ari, the Lion of the Atreides, and here --" Again he shook Ghanima's arm with that powerful ease which set her whole body jerking. " --here is Aryeh, the Atreides Lioness. We come to set you onto Secher Nbiw, the Golden Path."
-- Frank Herbert, Children of Dune, page 391.

The miniseries actually changes this scene quite a bit, and leaves the bit about Ghanima out entirely, but she is very much the Atreides Lioness as she walks down those stairs, prepared to defend her brother and the Golden Path from any and all who would dare abuse their power.

ofthe_wilds is because Morrigan is a Witch of the Wilds, a magic-user who lives outside the law in a primordial forest.

Other considerations were sneakywitchtheif (thank you, Alistair), prowls_shadows, vexes_templars, and like_kasaanda, all of which are variations on quotes said by-or-about her in canon.

harpy_daughter comes from the fact that Surreal's mother, Titian, has become the Queen of the Harpies in Hell. Not that Surreal knows this - yet - but it also fits because Surreal herself is kinda bitchy sometimes.

Alumni:
icecoldfrost is simply a play on Emma's last name and her nature. There's too many canonical references to Emma's cold heart to count, although I referenced my favorite one for her AU journal, cold_hard_heart: "I've had quite enough of these painful emotions....no empathy, no compassion, just a cruel sense of humor and a cold, hard heart."

dojima_hime In canon, Dojima's coworkers make jokes about the fact that she never has to do any work because "She's special" and gets called "the princess." So I went with one of the Japanese honorifics denoting a young lady of high birth.