Może napisać, "Został zabity podczas potyczki z Kotami" tak jak jest to napisane na angielskiej Wiki?

Well, this is also not the whole truth... He really died by the hand of Geralt, but it was an accident - and Gweld was influenced by a mage (if I understood everything right). I was thinking, the death of Geralt's former best friend (in the comic) is a very important and difficult situation, so it could be described a little bit more detailed - not only with "killed in action" ;)

To może tak: "Podczas potyczki z Geraltem na Gwelda zostało rzucone zaklęcie, któro miało spowodować, że zabije Geralta. Jednak gdy Geralt i Gwend upadali na ziemie to miecz Geralta przbił Gwenda, przez co ten zmarł"?

Okay, that sounds very good. :) And can you add also something about the whitening of Geralt's hair?

In my opinion it should be written in article about Gerald, but you can add "Po tym pojedynku włosy Geralta zsiwiały" lub "Po tym pojedynku włosy Geralda zmieniły barwę na siwą".

Is it okay » in this way?

Why "włosy Geralta zsiwiały z bólu"? :O

Tylko myślałam... ;) Geralt was hurt by the death of his friend and how he died...