I haven't been on the BBS in a long time.
Has Jemima Rooper been mentioned for T'Ryssa Chen?
She would be brilliant.
You mean Medusa from Atlantis
? I don't see any conceivable way in which she would be remotely right for T'Ryssa. She doesn't look a thing like Trys, she's the wrong ethnicity, and I don't see any similarities of personality.
The actress who plays Ariadne on Atlantis
, Aiysha Hart, is somewhat closer in appearance, at least (though she's Anglo-Arabic, not Chinese). Could that be who you were thinking of? I initially got a little confused about who was playing which character, since Rooper was listed in the main titles and Ariadne initially seemed a more central character than Medusa.