Practitioners summon ka from either their soul or stone slabs and use them to fight. The lifeforce of the ka is linked to its user's ba. Such battles were recreated in the modern world through the card game, Duel Monsters.
In the Japanese manga, "Diaha" and "Duel" are written with the same kanji, 決闘. When written with the furigana for the English word "Duel", it refers to a battle of Duel Monsters. When written with the furigana for the Egyptian word "Diaha", it refers to a battle of ka.