Oh, you have no idea how much I have to say about Shiver.
ok lets start:
we know of two girl beings: RAVANNA AND CULWYEH
Culwyeh: OK most of what we know about her comes from GURPS which I dont want to relay on as much as possible so I'll use more cannon stuff, like ground zero, the comix in which Reabican kills shiver. Shiver first uses her "silent dream" or her "whisper dream", this as we know forces Reabican into a surrael dream-duel in which shiver holds all the cards. Reabican uses knowledge from the head to break out of this dream and k33l shiver. cool.
So this Culwyeh is THE all mighty and powerful sorceresess that NO ONE (save moagim and the head) can break out of her whisper dream. In gurps it is said: culyewh has practiced magery for a LONG time in history. I believe that she existed during the wolf age, and was evil then. We also know she created the wights, which I still believe was really her in the very origin. that will also quelify that she is very ancient. She then falls in battle to reabican.
Ravanna: is a warrior girl that is good at melee combat, but has no magic knowledge. We dont see her at all during M1. I think when Soulblighter ressuercts shiver, he takes culwyeh's soul into ravanna's body.
There are a lot of similiraties between ravanna and culwyeh:
Culwyeh: is a poor general, she is easily out flanked in M1.
Ravanna: is also a poor general in M2, pregame text in landing at white falls tells us how she is outflanked by Bealdun (probably one of Alric's officers) and her rear guard is destroyed utterly. she can't win till the myrks help her.
Culwyeh: used to, or at least she thinks she looks real good. she has that mirror in her tent, and vanity is her weakness.
Ravanna: is said to look real good (m3 manual) and she is hot during M3 if you ask me.
we also know that Ravanna gets pissed off really fast in M2 when she talks with myrdered, and M3 manual tells us of ravanna that she gets pissed off real fast.
Of shiver's power as culyewh we know that she's very powerfull as a mage
When shiver is ravanna (m2) she still is, but way less.
From all this my conclusion is:
in M1, Shiver=culyewh, after level3, culwyeh = dead
in M2, culyewh's soul is ressuerected with ravanna's body
thats why she is less powerfull as a mage.
I still can't explain the similiarties that culyewh and ravanna had before the ressurection (appearance, poor tactician).