Guest Stars Donna Kimball voices Aughra Caitríona Balfe voices Tavra Mark Hamill voices The Scientist Keegan-Michael Key voices The Ritual Master Benedict Wong voices The General Gugu Mbatha-Raw voices Seladon Simon Pegg voices The Chamberlain Victor Yerrid voices Hup Harris Dickinson voices Gurjin Neil Sterenberg voices The Scroll Keeper Awkwafina voices The Collector Kevin Clash voices Gruenak #1 Warrick Brownlow-Pike voices Red-Haired Paladin Harvey Fierstein voices The Gourmand Lena Headey voices Maudra Fara Toby Jones voices Librarian Ólafur Darri Ólafsson voices The Archer Neil Sterenberg voices Gruenak #2 Shazad Latif voices Kylan Ralph Ineson voices The Hunter Hannah John-Kamen voices Naia Mark Strong voices Ordon Alice Dinnean voices The Ornamentalist Andy Samberg voices The Heretic Bill Hader voices UrGoh the Wanderer Louise Gold voices Maudra Argot James Dreyfus voices Lath'N Charlie Condou voices Mitjan Beccy Henderson voices Bobb'N