Lovely meme! Got me browsing icons for quite a while. ^^
Cassandra: The only one I can see in Lonneke Engel's place is Edyta Zajac.
Ereshkigal: Liya Kebede was love at first sight. Her modelling shots just have enough of the exotic to fit Eresh, and boy does the woman have a creepysmile. Kandyse McClure (Dualla from BSG) and Aaliyah don't come close enough to the depiction I had in mind, both too soft for Eresh, but they are the only seconds I could find.
Goth: I was torn between Nephania and Twiggx. But Nephania's hair was way too pretty to ignore, and she has more of a doll-like face than Twiggx does.
Pandora: It was either Indira Varma or Kerry Condon. Yes, Rome overload!
Raphael: He had me scrambling for quite a while, trying to find a PB which fit the general blond, familial look of the other angels. I stumbled on Ben Barnes and liked the idea, but it floundered when I realized he was taken by Huginn. I hadn't managed to find anyone else before Lily suggested Simon Baker, and he fit right into the aspect I had designed for him.
Skadi: Skadi was a pain. A major, major pain. I started with Elisha Cuthbert, realized how unbeatable that glare-smirk was, and then decided to go look for other possibilities. Silly me, there are none like her... But Taylor Swift and Claire Danes come pretty close.
Sleipnir: He was another one that never occurred to me to use anyone but Leroy Duivenvoorden. He does have some horse-like reminiscence, without looking horse-faced. On hindsight, Colin Morgan could also work pretty well.
Urania: I never quite pictured Urania as someone other than Mia Kirshner. It was just a question of finding a decent amount of straight long hair pics. Krysten Ritter is a bit too plump and young, but she might work as well.