Ragnarök: A Requiem for the Forgotten is an official webcomic by GRAVITY that serves to further flesh out the story of Seyren Windsor and the other adventurers that met a tragic end by machinations of the Regenschirm Laboratory. The story takes place between Episode 10 and 11 of Ragnarok Online and encompasses a total of 16 episodes released on a weekly basis.

(Source: Ragnarok Wiki)