He is a member of the Team Star Breaker, representing America in Big Bang Bladers. Jack is an artistically obsessed blader who makes works of art with his Beyblade, Evil Befall UW145EWD.
Jack has long wavy light burgundy colored hair. He wears a blueish-green jacket with yellow highlights with a purple shirt underneath. He wears white gloves as well as a black masquerade mask that leads to a point at the nose. Also he wears really dark blue lipstick.
In Beyblade: Metal Fury, he returns with an all new look. He removed the mask and face paint. He still has the blue lipstick and the white gloves. He swapped his original jacket for a grey one. Under that, he wears a teal shirt. He has brown trousers and a white and yellow belt. Jack has new black boots and wears something around his neck. The wardrobe change could be due to Jack being taken off the Arrangement System.
Jack comes off as strange to most people. He is very self-absorbed artist and seems to live in his own world most of the time. Anything that can't compare to art one way or another is worthless to him. Even in his battle style, his art obsession clearly shows - he doesn't beyblade for the sake of the sport, but rather uses it as a tool to create artworks. He's ruthless and absolutely uncaring of other people's well-being and easily willing to turn even a human being into 'art' by wounding him.
Jack's mental state appears to have become considerably unstable due to the influence of the Arrangement System. Destruction of his artworks causes him to break down immediately. Nevertheless, he states to love the system and its influence on him, even exclaiming it's a good thing that it changes ones personality. He himself, so he claims, has become more free for the world of art due to it, a thing for which he's thankful.
Socially, Jack clearly distinguishes between people he's interested in and everyone else. That differentiation is not made based on strength, as even Gingka or Masamune do not catch his attention. The only people Jack wishes to interact with are those who he deems elegant, like Ryuga or Tsubasa. Even here, he sees human beings as art rather than as people. He's very dettached and unable to comprehend other blader's emotions in any way.
By the time of Metal Fury, with the Arrangement influence wearing off, Jack's personality appears toned down and a lot calmer, although still similar to his old self.
Interestingly, 3 of the 4 Bladers in Hades City have their Bey related with Hades. Kerbecs is the Guardian Dog of Hades, Befall is the symbolism and Destroyer (Perseus) is the mythological heroes that borrows an invisibility helmet off Hades.