NITEMARE

You look this face, you are able to recgonize it in Forbidden Memories game or in Dark Duel Stories. But you probably don't know who is he, very well this section is for this also. Nitemare is doubtless, one of the personages of the anime (that wasn't presented in the Japan yet) more mysterious, we have very few information about him, barely that Nitemare was the big creator of the darkness game (despite of many may think that was Yami).

There are rumors that Nitemare will be the last one vilain from the series, he will be free by Henshin (personage that will be presented future in Japan) that free Nitemare uniting the 7 millennium itens. Nitemare he has two forms, the simple form, that he looks a man dressed in armor, and the perfect form, that it is presented above.
I think this is why Yami Dueled Yugi at the end, because the seven Millenium Items were united and Yami got all his memories back.
I still dont know why Yami wants to Duel Yugi.