What is Wyrdmarks?

Wyrdmarks represent the cryptic nature of Valg magic that threatens the human world. These symbols have great power, but characters like Chaol and Yrene do not understand them beyond the fact that they are relevant to defeat the Valg. This relates to the immense threat that Erawan and his forces pose because the world of the Valg is incomprehensible to the humans unless they learn more about its history.