Wait a sec guys...
If the lvl 50 Marik appear, then you can duel with him till you win?
So, i dont need to run to complete the "play 60 times with Marik" quest, because if i lose 60 times against him, it will mean i complete the mission? Am i correct?
Even before lvl 50 Marik was one Threshold Marik, that you need to defeat before it could progress. So you can farm with such a method the necessary battle count. Just not the win one.