I wonder how are they suppose to bring him tho. He didnt even duel once neither in the anime nor in manga. Nobody really even knows what kind of deck he uses.
I think I heard on the Reddit page that the Battle City event is two parts long. Maybe the first stage is the pre-finals of the tournament when Yugi dueled all of those Rare Hunters (hence the Arkana unlock), and then maybe you will be on the blimp and will have to duel the eight finalists, with Marik unlockable at the end.