Guest Stars Donna Kimball voices Aughra Benedict Wong voices The General Gugu Mbatha-Raw voices Seladon Keegan-Michael Key voices The Ritual Master Caitríona Balfe voices Tavra Simon Pegg voices The Chamberlain Jason Isaacs voices The Emperor Mark Hamill voices The Scientist Victor Yerrid voices Hup Neil Sterenberg voices The Scroll Keeper Awkwafina voices The Collector Kevin Clash voices Gruenak #1 Harvey Fierstein voices The Gourmand Warrick Brownlow-Pike voices Podling Servant #1 Warrick Brownlow-Pike voices Red-Haired Paladin Lena Headey voices Maudra Fara Ólafur Darri Ólafsson voices The Archer Neil Sterenberg voices Gruenak #2 Ralph Ineson voices The Hunter Alice Dinnean voices The Ornamentalist Andy Samberg voices The Heretic Bill Hader voices UrGoh the Wanderer James Dreyfus voices Lath'N Louise Gold voices Maudra Argot Charlie Condou voices Mitjan Beccy Henderson voices Bobb'N Theo Ogundipe voices The Sanctuary Tree