Knoll is a playable character in Fire Emblem: The Sacred Stones. He is one of Grado's royal mages who aided Lyon in his research into the Sacred Stones in an attempt to resurrect Emperor Vigarde. However, after Lyon used the Dark Stone to successfully resurrect his father, Knoll was then imprisoned for execution to keep the truth from being revealed. When Ephraim's group reaches the capital and defeats the Emperor, they discover and release him from the prison cell. After that, Knoll joins the army and provides them with information about Lyon's fall to darkness.
Knoll is kindhearted and very intellectual, but is secretive and rather elusive because of the troubling knowledge he holds. He rarely talks and keeps to himself mostly, possibly being secure or private-minded. In his support conversation with Lute, she attacks him, as she believes that he threatens her "natural superiority," and that since he uses Dark Magic, he is the enemy of light. In addition, in his supports with Natasha, he points out the differences in Dark Magic and Light Magic, dark being based in knowledge and light being based in faith.
He also seems to know most of the characters from Grado, such as Duessel and Natasha. Despite his aloof and taciturn personality, he is very passionate toward his country, and in his A support with Natasha, he promises her that he will join her in rebuilding Grado.