Shimon Muran

Shimon, known as Siamun Muran in the manga and Japanese anime, though not a priest, is a vizier of Pharaoh Atem. Solomon Muto is the reincarnation of Shimon. When Atem goes to the World of Memory, he initially confuses Shimon by calling him "Grandpa". The name "Siamun" is pronounced the same as "Shimon".

Anime and Manga
He was originally one of the Pharaoh Akhenamkhanen's original guardians, and he was granted the Millennium Key to hold. His Ka (or his monster spirit) that he summoned was "Exodia the Forbidden One" and he swore to seal it and never use it again after he destroyed the force that was attacking the Egyptian capital. He apparently gave up his position of guardian to Shada, and to him he relinquished the Millennium Key.

He plays a largely minor role in the Millennium World arc as first, as he introduces much of the ancient ways and terminology to the Pharaoh Atem.

When Zorc Necrophades rises and begins to march on the city, Shimon takes up the Millennium Key that Isis brought back and he summons Exodia to combat Zorc. Although Exodia experiences some success, especially after Siamun demonstrates its ability to regenerate after its arm was torn off by Zorc, Zorc overpowers Exodia since its power is based on Siamun's, while Zorc can draw power from the darkness. Therefore, Exodia is destroyed and Siamun is killed.

Simon Muran in Yu-Gi-Oh! Forbidden Memories
In Yu-Gi-Oh! Forbidden Memories, Simon Muran is the prince Atem's, tutor, attendent and card mentor. He taught the prince how to play the card game.

Depending on the player's actions, Simon can tell Atem the story of how the card games were used to Summon powerful monsters, causing chaos, therefore restricting the use of the cards to their kingdom. Also depending on their actions, they may duel him.

When Heishin attacks the palace, claiming to have uncovered great power, Simon is alerted. Simon, not fond of Heishin, confronts. Simon is badly beaten, when the prince arrives. Heishin demands to know where the Millennium Puzzle is. Simon secretly gives it to Atem and tells him to run. Atem is unable to escape and is forced into a duel with Heishin. After Atem loses, Simon convinces him to shatter the Puzzle.

After Atem breaks the puzzle, Simon seals Atem within the puzzle, leaving him on a mission to collect the power of the Millennium Items before returning to their time. Upon returning to his time, Simon bids The prince good luck and fades out of existence.

Deck
In Yu-Gi-Oh! World Championship Tournament 2004, Simon plays an Exodia Deck which includes some Beatdown monsters as well as Spell and Trap cards to deter the opponent. This Deck has a twofold function, either to stall the opponent's progress until all five Exodia cards are drawn or rout the opponent's Life Points if the five cards cannot be immediately obtained.

Trivia

 * His ka is Exodia and his present day self Solomon Muto plays an Exodia Deck in World Championship 2004.