This has bugged me throughout the Witcher 2.

The assassin Geralt killed at the end of Witcher 1, saving Foltest.

Who was he? He's never mentioned by Letho at the end of the game, we only learn about Auckes and Serrit. I think you see Letho with 3 accomplices in some of the flashbacks, but this guy doesn't seem to exist and presumably tried to kill Foltest before (or at least around the same time) as Demoved.

That's a good point. My guess is that the designers didn't want to confuse too many new players who hadn't played the first game. To me it's clear he must have been working for Letho, but I hadn't thought about the fact that he's never mentioned in the second game.

Maybe there are several Viper school witchers wandering around Nilfgaard, and he was recruited separately from Letho & friends? I know Letho says that the Viper school was destroyed but I don't remember if he says that Serrit, Auckes, and himself are the last surviving members.

Viper School disciple. Witcher check, on assassin's mission, check, tried to kill a king, check, only name unknown. Not of importance, since already dead, correct?