Challenge Mode - challenge set 4 (prob solved thanks)

hi
sorry if this has been posted before, but how do you do challenge set 4, #9 'enter the dragon', anytime i enter it i automatically lose without the game even starting, reason being the card 'kozilek, the butcher of truth' says locked, chal 4 #9, im assuming that means i need to do that challenge to use this card, thanks for any help.
sorry if this has been posted before, but how do you do challenge set 4, #9 'enter the dragon', anytime i enter it i automatically lose without the game even starting, reason being the card 'kozilek, the butcher of truth' says locked, chal 4 #9, im assuming that means i need to do that challenge to use this card, thanks for any help.