How's about a battle contest. But in three rounds. 
 
During the first round it is chosen who can fight who. Somebody picks a hero/villain and fights somebody else, in a tournement. All the fights are voted. And the places during the tournament are randomly chosen by the staff so you never know who has the advantage. At the end there will remain 4 battles, think of it as the quarter finals. 
 
During the second round the four battles get drawn by the artists of the vine. Again the outcomes are voted but also the drawings. 
 
During the third round the two best artists draw the semi-finals. We vote who wins. 
 
Finale: everybody gets to draw the finale. Only drawback is that the previous two artist get a head start. We vote for the best drawing, the winner. S/He who has the most point wins this tournament together with the remaining hero/villain.