Age: 140 (Chronological Age)
The hero of 100 years ago and the one who 'defeated' Glen Baskerville. He is revealed to have some sort of connection with Alice's memories and Raven's past. Jack looks uncannily like a grown-up Oz with a long plait. His personality is also quite similar; he does things at his own pace and is loud and cheerful. Oz and Gilbert meet him when they are taken to the Cheshire Cat's dimension. He is currently residing in Oz's body and can 'possess' Oz and speak through him. When in control, Jack also has full control of Alice's chain power. Jack was the third son of the Vessalius family who was, before the Tragedy of Sabrie, a third rate noble family. Thus, with no expectations from his family, he acted quite freely: always smiling, joking and flirting with girls.
Jack was also a self-proclaimed music box maker. His best friend at that time was Glen Baskerville. Jack crafted a pocket watch for him and Glen wrote the melody, titled "Lacie". The pocket watch's melody was said to be a song that Lacie always sang to herself. Later, Jack killed Glen because he started the Tragedy of Sabrie and tried to kill Jack. Although hailed as a hero for this act, Jack did not want to kill his best friend. In a later entry in Jack Vessalius's diary, he wrote: "I have killed my best friend. Please... Please do not call me a hero." He also shows true anger when Lotti suggested that he killed Glen to gain fame and glory. Jack reveals, through his speech when he first possesses Oz, that Glen is still living. Despite this, he says to the Baskervilles that if they wish to repeat the past, then he will once again turn his body into a blade that will destroy the Death Gods.
