Marik plays a variety of Decks while controlling the bodies of various individuals through the Millennium Rod. Marik's main deck is never seen in the anime and manga. Once his body is taken over by Yami Marik, he creates a new deck. For those Decks, see Yami Marik's Decks.
"Infinite Cards": Removes hand limit, allowing the ATK of "Slifer" to climb virtually infinite.
However, despite Marik's claim that this combo would allow "Slifer" to have infinite ATK, Yami Yugi proved otherwise, as he brainwashed "Revival Jam" and had "Slifer" constantly attack the reviving monster, forcing Strings to keep drawing until a Deck Out occurred, thus losing. Therefore, this combo's greatest weakness is the ATK of "Slifer" is limited by the number of cards within the player's Deck.
Marik is a Tier 5 Duelist, unlocked after defeating the "Ghouls" (randomized Duels against the five Tier 4 Duelists) five times in a row. Defeating him unlocks the individual Tier 4 Duelists as opponents.
His Deck is designed to destroy his opponent's monsters and hand, with elements of Deck Destruction as well. Many of his monsters have dangerous Flip Effects and weak ATK/DEF-Marik covers the latter with his destructive Spells and Traps.