Well, unlike Geralt, they can teleport.
Also, why would Geralt be in Touissant?
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It's doubly funny if you've read "The Sword of Destiny" as Priscilla is obviously based on Desi "Little Eye" who is one of GERALT'S love interests.
Yes sorceresses can teleport. Now why isn't Triss at Kaer Morhen again?
Yeah i have trouble with idea of Geralt going to Toussaint in the first place. They'll have to give a valid story reason to divert there. Teleporting with Sorceresses might at least expedite the diversion.
Read that short story. There's a line where it says Dandelion refusing to sing his ballad about Essi after an event happens. Made me wonder if Dandelion would retire his famous ballads about Yen-Geralt if Geralt goes off with Triss. Probably not.