Darknite can also transform into his true form known as Nitemare.
Yu-Gi-Oh! Forbidden Memories
Darknite/Nitemare debuts in this game as an actual villain. Darknite was sealed away in the Forbidden Ruins and, as stated above, is famous for the creation of the Shadow Games, which when one loses, is sent to the Shadow Realm. Darknite can only be released when all seven of the Millennium Items are brought to his tomb.
Heishin, a power-hungry advisor, brings all of the relics to the ruins in order to awaken him. Once there, Heishin attempts to make a pact with Darknite to help bring him higher to power. However, Darknite expresses no interest in the bargain. Heishin pleas with Darknite, however he grows pestered with the conversation and turns him into a card. He then comments that it is "the most noisy and ugly card he had ever seen". He then burns the card (likely murdering Heishin) saying that it doesn't belong in his deck.Darknite then faces to Atem and Seto who had seen this entire event and claiming they would be excellent additions to his deck. Atem then reveals the Millennium Item Cards to Darknite, forcing him to back off. However, if doesn't last long and ultimately Atem must duel Darknite. After losing to Atem, Darknite becomes extremely enraged and transforms into Nitemare, demanding another duel with a far more powerful and impressive deck. Despite this however, Atem defeats Nitemare again, which sends him back to where he once came.
Yu-Gi-Oh! The Falsebound KingdomDarknite serves as the final boss of the game and is released by Scott Irvine after Kaiba and Yugi destroy his virtual world. Darknite proclaims that "the price for interfering with a minion of darkness was high" and tries to swallow the souls of the hero. Darknite fails, and battles them with one of the most powerful monsters in the entire game: An Egyptian God (varies on who you play as). After beating Darknite, the virtual Kingdom will shut down forever.
It is possible to face Darknite again, and he will transform into Nitemare with his Egyptian God having maxed-out stats and impossible to weaken like his fake form.
Yu-Gi-Oh! Dark Duel Stories
Darknite/Nitemare is the final boss of the handheld game Dark Duel Stories and debuts in this game though not in significant villain role. His role as an antagonist here is downplayed and seems intensification. His only purpose to "eat the player's soul" because he has proven to be the best due to the player succeeding in things even he couldn't do. Besides that, he also has some of the most powerful cards in the game.
Yu-Gi-Oh! Duelists of the roses
While Nitemare himself doesn't appear in this game, Manawyddan fab llyr implies he's out to avenge his brother who was sealed in Egypt in Forbidden memories.