Greiger

Bommer is a participant in the Fortune Cup. An honorable duelist, Bommer is prideful yet stoic. Likely of Southwestern Native American origin, he comes from a destitute village which he duels to provide financial aid to.

Yliaster used Bommer's village as the site of an "experiment" to summon the Crimson Dragon, which completely destroyed the village. Knowing information which Yliaster doesn't want anyone to know, Bommer is involved in some sort of compromise with Rex Godwin, agreeing that KaibaCorp will provide aid for the reconstruction of the village in exchange for becoming involved in identifying the Signers within the Fortune Cup.

His first match is against Ruka, but as her brother is substituting for her, he ends up dueling a disguised Rua instead. Though Lua puts up a valiant fight, Bommer wins easily, never even being intimidated. During the break between his match and the next match between Aki Izayoi and Jlil deLauncebeaux, Bommer is stopped in the hall by Jeager, who informs him that he dueled the wrong twin. Bommer's opponent is the semifinals is Yusei Fudo.

Enraged at not being able to help his younger brother and sister, Bommer decides to take revenge on Godwin for his village's destruction. Bommer uses his Duel Runner to rocket toward the box room, intending to kill Godwin, Jeager, and Jack. Yusei attempts to stop him, but one of the spikes on Bommer's Duel Runner flies off and crashes into the box. Godwin catches it with his prosthetic hand.

Bommer and his people are descendants of the People of the Stars, having knowledge of the Crimson Dragon and the Signers, as he stated that, if he lost, he wanted to be defeated by one of the Five Dragons.

Deck
Bommer plays a Reactor Deck. His monsters are based on aircrafts and inflict damage to his opponent whenever a specific type of card is played.