Yu-Gi-Oh! Duel Monsters 4: Battle of Great Duelist is a Japan only Yu-Gi-Oh video game for the Game Boy Color, and the fourth installment in the Duel Monsters series. It was released December 7, 2000 as three separate versions (Yugi, Kaiba, and Jounouchi), each being able to use only a certain selection of the 900 available cards.
Each of the god cards are usable after completing the game, but they can only be obtained from a different version by trading:
● Slifer the Sky Dragon can be used in the Yugi Deck version, obtained in the Kaiba version by defeating Yami Yugi.
● Obelisk the Tormentor can be used in the Kaiba Deck version, obtained in the Jounouchi version by defeating Yami Bakura.
● The Winged Dragon of Ra can be used in the Jounouchi Deck version, obtained in the Yugi version by defeating Marik.