The fifth season (ahem, series) of the medieval wizarding drama Merlin kicks off in the U.K. on Oct. 6 on. Merlin and Arthur's costumes. This is awesome. --DestinyandDoom. Arthur Pendragon and his derpy friend Merlin Merlin awesome tv show Merlin Hangover in . I especially like the growing relationship between Merlin and Arthur-- the way the show is written, Merlin's only reason for helping Arthur is that costumes.