Vex Replica No. 44

Vex Replica No. 44 is a replica created by Vexen in his own likeness. He makes his sole appearance in the  manga.

Between Kingdom Hearts Birth by Sleep and Kingdom Hearts II
To ensure his life's work is carried on, Vexen creates forty-four replicas of himself. As its name implies, the last of these replicas to be created is Vex Replica No. 44.

Kingdom Hearts II
Following his defeat in Beast's Castle, Xaldin encounters the Vex Replica upon his return to The World That Never Was. Upon being confused for the original Vexen, he removes his wig, displaying his number and stating he is one of Vexen's replicas. Xaldin claims to see through the replica's claims that they were created to carry on his knowledge, accusing Vexen of having created the Replicas knowing his days were numbered; with that, Xaldin summons his lances and attacks him. The Vex Replica retaliates, however, and summons Vexen's shield to block the attack, then subsequently freezes the attacker. The replica looks up at Memory's Skyscraper and bids farewell to the Organization. As he leaves, he ponders what the heart truly is as he vows to return with the answers he will find.

Later on in Twilight Town, he discreetly observes Kairi and the Twilight Town gang through a peephole within the corridors of darkness. He notes how easily they become friends and how that moment would be the only chance to study Kairi, as she was a person who possessed no darkness in her heart. Upon Saïx's arrival and subsequent kidnapping of Kairi, the replica departs to preserve his existence.

The Vex Replica is last seen at Castle Oblivion in the manga’s epilogue. There he has published his own Vexen Report, in which he summarizes his compiled knowledge of hearts and the connections they forge. His purpose established by his creator fulfilled, the Vex Replica, with satisfaction, declares his journey over and bids a respectful farewell to the warriors of the Keyblade.

Design
As a replica, Vex Replica No. 44 looks identical to Vexen, the main difference being that he and the other Vex Replicas are created bald. The Vex Replica has his number written on the upper part of his forehead. He wears a wig identical in appearance to Vexen's hair.