one of his unlock missions is to "use level 3 or lower monster cards 3 times in a duel against him" i have already summoned 3 different level 3 monsters in a few duels but still failed. what is it supposed to mean?
For me, I used 3, 3 star EFFECT monsters and had their effects activated and it worked. I had used 3, 3 star normal monsters and nothing happened. I literally had no monsters in my deck besides 2/3 star effect monsters and spell/trap cards. Once I won the duel, Yami Bakura was finally unlocked.