He only appears in-game after the player claims his Character Unlock Mission reward for defeating Legendary Duelists 50 times.
Intercontinental champion Bandit Keith has no qualms about using underhanded tactics to steal the win. His signature monster "Barrel Dragon" has an effect that enables it to destroy his opponent's card.
Immediately after the player claims the reward for Bandit Keith's appropriate Character Unlock Mission, they will encounter Bandit Keith for the first time. He remarks to himself that this is the Duel World that the "Kaibacorp dweeb" created, before declaring that Kaiba's a fool; he can't believe that he can Duel all he want in Duel World for free, saying that he himself would charge a "bazillion." Bandit Keith then reveals that he's not interested in becoming the Duel World King, unless there's a cash prize involved, whereupon he reasons that there should be a "ransom of riches" for the Duel World King. Even if there isn't, he continues, he can steal the data in this world and sell it to the highest bidder. He then chuckles, before bursting into arrogant laughter.
Until the player defeats Bandit Keith for the first time, whenever they challenge Bandit Keith to a Duel, he will first chuckle, and then state the player must be joking, before rhetorically asking the player if they really think they can beat a genius like him. He goes on to exclaim that they don't need to Duel, as even the player knows that Bandit Keith is going to beat him to a pulp. He then tells the player to face facts - they're getting "thumped," before laughing and then telling the player, "Step right up to get smacked down!"
Until the player manages to defeat Bandit Keith at least once, whenever they lose to him, Bandit Keith will declare this is why he's the champ and the player is the chump, as the player is a "dweeb" who doesn't have either the cards or the tactics to take him down. He then chuckles, before revealing to the player that although he sometimes cheats to win, he didn't need to in their Duel since the player was incredibly weak, concluding his dialogue in laughter.
Upon Bandit Keith's first defeat, he initially seems to downplay his loss, before suddenly blaming Kaiba - he would have won if Kaiba hadn't "rigged" the rules against him. He then swears that he'll show "all you punks" that he'll get the last laugh, concluding his dialogue in laughter.
After the player redeems their final unclaimed reward for Bandit Keith's Character Unlock Missions, they will encounter Bandit Keith again, who asks the player if they've ever risked everything they cherish - their dreams, their cards, or even their life. He then explains that he only asks this because he himself has, which taught him a real lesson: if you aren't willing to risk everything, then you're worth nothing. He promises he'll never be worth nothing, which is why the player has no clue what he'll do to reach the top, such as him using "Barrel Dragon" (which he shows to the player). He then chuckles, asking the player how it feels for them to be in the sights of "Barrel Dragon", before bursting into laughter.
Return 1 card in your hand to your Deck and draw another. The skill can only be used once per turn and twice per Duel.
Sleight of Hand
Can be used each time your Life Points decrease by 1500. Add 1 7 Completed card, hidden in your wristband, to your hand. This skill can only be used once per turn and twice per Duel.
Can be used after starting hand is distributed. Shuffle all the cards from your hand into the Deck. Then draw the starting hand again.
If one of your monsters of Level 5 or higher is destroyed in battle, in your next Draw Phase a normal draw gives you 2 cards.
If your Life Points are at least 1000 more than opponent's, and if you have at least 5 cards in your hand, your coin tosses always land on heads.
Can be used if your Life Points are at 1500 or below. Select and take control of 1 card Set in your opponent's Spell & Trap Zone. This skill can only be used once per Duel
Whenever Bandit Keith Summons "Barrel Dragon", a cut-in frame of Bandit Keith will briefly appear, and he'll announce "You won't be able to survive this kind of firepower!" followed by "Here comes Barrel Dragon!" If that player hasn't already Summoned "Barrel Dragon" during that Duel, a cutscene of "Barrel Dragon" being Summoned will play afterwards.
Whenever he activates the effect of "Barrel Dragon", he announces "Barrel Dragon's effect activates!" followed by "Proton Blast!"
Most of the time when he declares an attack with "Barrel Dragon", he announces "Pulverize that punk!" followed by "Barrel Dragon, attack!"
Whenever Bandit Keith Summons "Launcher Spider", a cut-in frame of his face will briefly appear, and he'll announce "Go, Launcher Spider!"
Most of the time when he declares an attack with that monster, he announces "Launcher Spider!" followed by "Shock Rocket Attack!"
Whenever Bandit Keith Summons "Slot Machine", a cut-in frame of his face will briefly appear, and he'll announce "Time to test your luck!" followed by "Slot Machine!"
Most of the time when he declares an attack with that monster, he announces "I attack with Slot Machine!"
Whenever Bandit Keith Summons "Machine King", a cut-in frame of his face will briefly appear, and he'll announce "Take the crown, Machine King!"
Most of the time when he declares an attack with that monster, he announces "Machine King attacks!" followed by "Jet Punch!"
Whenever Bandit Keith Summons "Pendulum Machine", he announces "I got a well-oiled machine all ready for ya!" followed by "Pendulum Machine!"
Most of the time when he declares an attack with that monster, he announces "Pendulum Machine's goin' into overdrive!" followed by "Slashing Blade Attack!"
Whenever Bandit Keith activates "Stop Defense", he announces "Hehehe... I activate my Spell!" followed by "Stop Defense!"
Whenever Bandit Keith activates "Metalmorph", he announces "I activate the Trap Card, Metalmorph!"
Whenever Bandit Keith activates "7 Completed", he announces "I activate my Spell, 7 Completed!"
All three of Bandit Keith's skills are based on his tendency to cheat during his Duels in the anime.