Millennium Key

The Millennium Key's (also known as the Millennium Ankh) primary unique ability is its power to unlock the doors of a person's soul, giving the user access to the "Room of the Soul," where their thoughts can be observed, or the "room" can even be "redecorated," allowing the user to alter a person's personality. Additionally, it can make the user, and others, invisible, and may or may not allow them to sense any disruption of the Sennen Items' mystical energies that would be cause by an item being taken from its rightful owner. The owner of this item may also force images, scenes, or visions into the minds of others and may or may not give the holder the ability to communicate telepathically with others, depending on the circumstances in a given situation.It is in the shape of an ankh, the Egyptian symbol of life (thus leading some to refer to it as the Millennium Ankh), and is the only Millennium Item without an eye. After it was made The Millennium Key was given to Solomon Muto's Egyptian alter ego, Shimon, but later it was passed on to Shada. 3000 years later, when Yugi solves the Millennium Puzzle, it's in the hands of Shadi, along with the Millennium Scale.

Bandai OCG
Millennium Key

This card is defeated in battle, but you can look at your opponent's hand and choose the next 2 cards that they will play and use to battle.