In the Duelist Kingdom tournament, Bonz, Sid and Zygor met Bandit Keith, who agreed to coach them through the tournament, so all four of them would advance to Pegasus Castle. Keith wanted revenge against Maximillion Pegasus for humiliating him in the final match of the Intercontinental Championship. While helping them win Duels the first day of the tournament, Keith secretly intends to use them for their Star Chips. When Keith finds out about Yugi Muto, Joey Wheeler, and the rest of the gang, he plans to get in their way and eliminate them.
When Joey runs away from the group towards a waterfall, Zygor beats him unconscious, and he wakes up in cave with a Dueling Arena, complete with a Graveyard Field. Bonz challenges Joey to a Duel that he tricks him into thinking he must accept.
Bonz has the upper hand, as his Zombie-Type monsters gain a 30% ATK and DEF bonus because of the Graveyard Field, and when they are destroyed, they just regenerate, and become even stronger from "Call of the Haunted". However, when Yugi and the gang arrive, Joey manages to figure out the Zombie's main weakness and that is their DEF is 0. Using "Shield & Sword" to switch their ATK and DEF values, Joey wins the Duel. Bandit Keith then locks the gang in, double crosses his three companions, and enters the Duelist Kingdom Finals after taking Zygor and Sid's five Star Chips by force.
Bonz, Sid, and Zygor are then seen right before the Battle City finals. The three reside in a nearby cemetery and trick people into giving up their Locator Cards. However, Yami Bakura is not intimidated by their act and challenges them to a Duel in which the winner gets all the Locator Cards, and thus goes directly to the Battle City Finals. Bakura wins in just a few moves, and then banishes them to Hell (the Shadow Realm in the dub).
*Disclosure: Some of the links above are affiliate links, meaning, at no additional cost to you, Fandom will earn a commission if you click through and make a purchase. Community content is available under CC-BY-SA unless otherwise noted.