Billy has long hair like Julie, except his hair color is yellow. He also wears a t-shirt and a orange and black jacket along with it that has a lightning bolt on the back, wears black fingerless gloves, and a hat that also has a lightning bolt on it.
Billy debuts as a Subterra player together with Julie, where he defeated Julie with his Cycloid. He was later defeated in a rematch by Julie's Gorem.
He becomes the top tenth brawler in the world before he becomes one of Masquerade's henchmen, when he's exposed to the Silent Core. He reappears as Masquerade's henchman, along with Komba O'Charlie, and battles Julie and Shun Kazami. Although he loses, he isn't freed from the mind-control. As Masquerade's henchman, the others often make fun of him since he is the only one in double-digits and is lower-ranked than the rest of them.
Later, when Julie attempts to bring him back to his senses with a battle, he nearly sends Julie and Gorem to the Doom Dimension, but after seeing the toy he had given her when they were young, he still defeats her but right before Gorem is sent to the Doom Dimension he takes out the Doom Card. He is then freed from Naga's control and Billy explains to the Brawlers how he first met Naga.
During Masquerade's quest to strengthen Hydranoid, Cycloid is sent to the Doom Dimension. However, Cycloid (along with the other Top Brawlers' Bakugan) is later freed and reunites with Billy.
He agrees to help everyone stop Naga's minions, and slows Rabeeder's approach on the city though he couldn't completely stop her. He returns to help Julie and Nene fight Tricloid. After they defeat her, Billy and Julie discover they have true feelings for each other, and starts dating. Afterwards, he helps the rest of the brawlers beat Centorrior and Druman eventully winning. He then gets sad to let Cycloid go.
Billy is first mentioned when Julie says that he was traveling the world to learn from famous athletes, and he was currently living in Spain. He is later mentioned to have moved to Africa to build schools, and finally appears in-person when the Vexos are hunting down the Resistance for the Attribute Energies. He and Julie tag-team against Ace Grit, but are easily defeated. Billy's surprise visit, however, had an unexpected side-effect: it led Mylene Farrow and Shadow Prove right to the brawlers' hide-out.
Bakugan Battle Brawlers
- Subterra Cycloid (Guardian Bakugan)
- Subterra Wormquake
- Subterra Hynoid
- Subterra Tuskor
- Subterra Rattleoid
- Subterra Centipoid
- Subterra Manion
- Subterra Mantris
- Subterra Terrorclaw
- Subterra Saurus
- Billy calls Julie BakuBabe, which seems to annoy her.
- His hat resembles Ash Ketchum's Indigo League Expo hat, which Ash wore in the first five seasons of the Pokémon anime. Also, in Brazilian Portuguese dub, they're both voice by Fábio Lucindo.
Bakugan Battle Brawlers
|Bakugan: Battle Brawlers|
|Klaus von Hertzon, Julio Santana, Chan Lee, Komba O'Charlie||No Outcome|
|Shun Kazami and Julie Makimoto (Tag with Komba)||Lose|
|Rabeeder and Darkus Garganoids (tag with Unknown Bralwers)||Lose|
|Tricloid (Tag with Julie and Nene)||Win|
|Centorrior and Druman (Tag with Dan, Marucho, Runo, Julie, Klaus, Julio, and Komba)||Win|
Bakugan Battle Brawlers: New Vestroia
|Bakugan: Battle Brawlers: New Vestroia|
|Ace Grit (Tag with Julie)||Lose|