Shadi is a man of mystery. He calls himself, the "Messenger of Anubis" and goes around punishing people who have desecrated Egyptian tombs. And so he traveled to an Egyptian exhibit in japanese university. There he came into contact with Yugi who was adorned with the Millenium Puzzle.

Shadi has his own Millenium Items, the Millenium Scale and the Millenium Key. The scale the one used in egyptian legend, where a person's heart is weighed against the Feather of Truth. If the heart is bad, it is devoured by Amut, a demon known as the Devourer. The key allows Shadi to enter a person's 'Heart room' which is who the person is. Once in the 'Heart Room' Shadi can control a person's actions.

Most people have one heart room, but when Shadi entered Yugi's he found two doors. One for Yugi's normal self, which was open contained toys and games. But he also found another closed door. On the door was the Sennen Eye Symbol.

He opened the door in hopes of finding the secrets of the Millenium Puzzle. The walls of the rooms was inscribed with heirogylphs, and in the center stood Yami Yugi. Yami Yugi challenged Shadi to a game. Shadi lost but promised to return to challenge Yugi again.

When Shadi returned he used his power to gain control of Anzu and forced Yugi into a game, so as to see Yugi's true power.Shadi has the same gaming skills as Yami Yugi, but Yugi is more resourceful. Once again Shadi was defeated, and Yugi explained to him that his power is friendship.

A portrait of Shadi can be found at Pegasus's castle in the Duelist Kingdom. He was the one who bestowed the Millenium Eye to Pegasus and all the pain that came with it.