The Duality Monsters (デュアリティモンスター Dyuariti Monsutā) are a new mechanic created by The Nepfessor. They have a black and white border that is split vertically, and they reside in the Extra Deck. They are stored in the Extra Deck, and in place of the Level, they have a symbol called Yin-Yang, depicted by a Yin-Yang symbol. For their Summon, you need to turn face-up banished cards face-down, as many as the materials tell. However, if they would be sent from the field to the GY, they are banished face-up instead, and can be re-Duality Summoned from while they are banished, by banishing materials from your GY. However, the aforementioned action can only be done once per turn.