Advent Decks allow holders to sense the presence of Mirror Monsters and see into the Mirror World/Ventara. They are initially equipped with a Seal Card and a Blank Contract Card. When inserted in a V-Buckle, can change the owner into a Blank form Kamen Rider (Ryuki/Dragon Knight and Ouja are the only ones seen with Blank forms). To become stronger and obtain more cards, the owner must use the Contract Card to form a contract with a Mirror Monster. Each deck has different weapons and abilities based the Rider's Contract Monster. All decks include an Advent/Attack Vent Card that summons the Contract Monster and a Final Vent in which the Rider and Contract Monster do a combination attack. Besides these cards, there are different categories of Advent Cards, e.g. Sword Vent, Strike Vent, Guard