Zuline didn't believe it worked after so long trying to convince Jäwell to learn how to read, to learn something, anything. From the ones who tried to teach him, Miroïr had a nervous crisis, Zarkhaïm surrendered, and Ajira cried after he insulted her in anger when she told him there were many languages, and every one failed.
Jäwell spent centuries using the portraits from history books in Zarkhaïm's library as targets for his knives and bows training. Using literature as a matter to start a fire in the commanding room to grill meat with the dwarf's leader. After all of this, just like that, Jäwell agreed to learn something that he considered useless, writing.