This is what really got my attention though. Just before Tristan's arm gave out, he was grabbed by none other than Shadi! He pulls the two of them up, and when Tristan looks up to thank him he is gone (typical of Shadi). Duke asks him who he's talking too, and Tristan says the man in white, to which Duke responds "what man in white?" Even though Duke was looking up at where Shadi would have been, he hadn't seen him!
So, this made me think. So far the only ones to have seen Shadi have been Yugi, Pegasus, Marik, and Isis, all four of whom own a millenium iteam. Is it possible, then, that only millenium iteam holders can actually see Shadi? And if so, then why could Tristan see him? My answer to this is fairly simple, Tristan has a millenium iteam that he has not yet claimed.
My theory about Yami's and Millenium Iteams is thus, though there isn't really any evidence to prove this: Each Millenium Iteam has a Yami, that will only awake when it is given to their reincarnation (Yami and Yugi, Marik and Malik, Ryuo and Bakura). So it's possible that the other four iteams we know about, the necklace, the scale, the key, and eye, have Yami's just waiting for the right person.
If this is correct, then there are four people awaiting their iteams, and if I'm right those four will be Kaiba, Tea, Joey, and Tristan.
