 Though the actor enjoyed playing the part of Brainiac , Marsters did have an initial apprehension about taking the role . As he is familiar with Brainiac from the comics , Marsters did not wish to be turned green and wear the character 's traditional pink outfit . The actor had to do little research on his character , as Brainiac 's original back story only consisted of a few comic book panels . Marsters believes his character wants to get rid of the humans because they are doing nothing but destroying their own planet , and Brainiac sees it as his duty to perform " pest control " on the species . The actor was going to appear in season six , but because his scheduled filled , the producers wanted to " close the door " on this storyline , so they " killed " his character . Later , Marsters was approached by Gough and Millar about returning to the show for its seventh season ; this time Marsters had free time in his schedule , and was able to return for four episodes . 
