Oblivion key

The Oblivion (過ぎ去りし思い出 Sugisarishi Omoide?, lit. "Passing Memories") is a Keychain that is found in Kingdom Hearts, Kingdom Hearts: Chain of Memories, Kingdom Hearts II, and Kingdom Hearts 358/2 Days. It also appears as half of Roxas's dual set of Keyblades alongside the Oathkeeper, and was transformed from the second Kingdom Key Roxas obtained after absorbing Xion. Fundamentally, the Oblivion is symbolic of Sora's memories of Riku.It is unknown why Denvor obtains it but it has chosen him as it's wielder.

Apperence
Oblivion is similar in shape to the Kingdom Key, though is deep black and has a longer reach. The hilt guard is comprised of two bat-like wings extending downward. The teeth are in the shape of the Kanji for "darkness" (闇). The keychain motif is a black version of Sora's crown necklace. The zipper-like pattern along the blade are also reminiscent of an Organization XIII Black Coat. The diamond in its hilt also resembles the diamond in the original logo of Hollow Bastion. When the Oblivion is summoned in Kingdom Hearts II, black smoke and violet sparks surround it.