17 cards where the name includes “door” and (the card is available on Paper)

Bar the Door (Dark Ascension #2)
Break Down the Door (Duskmourn: House of Horror #170)
Cellar Door (Innistrad #218)
Do or Die (Invasion #102)
Doorkeeper (Iconic Masters #53)
Doorkeeper Thrull (Murders at Karlov Manor #13)
Door of Destinies (Commander 2017 #208)
Doors of Durin (The Lord of the Rings: Tales of Middle-earth #199)
Door to Nothingness (Magic 2013 #203)
Evolving Door (Streets of New Capenna #144)
Giant Trap Door Spider (Ice Age #293)
Guardian of the Great Door (The Lost Caverns of Ixalan #16)
Kick in the Door (Adventures in the Forgotten Realms #153)
Matzalantli, the Great Door // The Core (The Lost Caverns of Ixalan #256)
Matzalantli, the Great Door // The Core (The Lost Caverns of Ixalan #256)
Maulfist Doorbuster (Kaladesh #123)
Orazca Puzzle-Door (The Lost Caverns of Ixalan #68)
Secret Door (Adventures in the Forgotten Realms #71)

It is the moment of discovery, the triumph of the mind, and the end of these results.