The members of the Dark Bladers were originally humans that were turned into soulless monsters after wishing for more power. Their aim was to capture and destroy any Bit-Beast they came across as revenge for their losses in the past. They reform after watching the Bladebreakers battle the Majestics.
The Bladebreakers first meet Cenotaph in England where he steals Tyson's Beyblade and attempts to force Dragoon out of it. Max and Ray go to help but are helpless against Sarcophalon. Cenotaph was close to succeeding until Kai joined the fray. He traps Sarcophalon in his own bandages and ultimately freed the Bladebreakers' Beyblades. Cenotaph tells the team that it isn't over and phases out.
Kenny begins to have nightmares about Cenotaph and Sarcophalon, worried about meeting more people like him. A cloaked figure stands outside their hotel, looking up at Kenny's room and speaking ominously. The Bladebreakers leave London, headed for Paris, on a train that runs through the English Channel. However, a train employee mentions that the train was supposed to be sent for repairs and realizes something isn't right (The train wasn't scheduled to leave yet or from that platform in the Dub). It turns out that Cenotaph has taken control of the train. After the Bladebreakers find out they're alone on the train, it suddenly brakes before reaching its destination. Tyson, Max, Ray and Kai step get out to investigate, where they come face to face with Sanguinex, Lupinex and Zomb. Kenny decides to stay near the train door, but also notices the sudden appearance of the three monsters. Before he can gather any data on them, he gets cornered by Cenotaph. Meanwhile, the Dark Bladers introduce themselves and Sanguinex challenges Kai. He refuses twice, even after Cenotaph uses Kenny to force his hand so Tyson takes his place. The battle begins and Tyson quickly goes on the attack. Lupinex, noticing his brother struggling, launches his Beyblade and with both of them attacking, they start to overpower Tyson. Max decides to even things out but when the evil Bit-Beasts are unleashed, Kenny notices that they are absorbing Dragoon and Draciel's power. He shouts out that they must have a weakness. Tyson remembers the movie they watched on the train and that Dracula's weakness is a cross. He and Max create a cross using their Beyblades, blinding Draculor who self-destructs. Max knows that silver will be able to defeat Lycanlor but he doesn't have anything so Ray inserts the silver coin he found on the train into Driger, launches it and attack Lycanlor. Zomb and Cenotaph pull out their Beyblades but before they can do anything, a rescue vehicle arrives. Without any choice, the Dark Bladers leave but not without forgetting to tell Bladebreakers that they haven't given up.
In Paris, Kenny has a nightmare about being attacked by the Dark Bladers atop the Eiffel Tower while the Dark Bladers are seen standing on the Eiffel Tower and discussing their plans. While Kenny and Tyson are observing the sights of Paris on the Eiffel Tower's observation deck, they see Zomb clinging to the window outside. Max and Ray hears their screams and races to the the elevator. Zomb disappears but reappears inside, with the rest of the Dark Bladers in tow who are in launching positions. Max and Ray meet up with Tyson and Kenny, also ready to battle, but they're outnumbered without Kai. Before the battle, Sanguinex explains the reason for their actions.
A few months prior, the Dark Bladers were still human and had competed in the European Cup. However, each lost to a Bit-Beast wielding Blader. They blamed Bit-Beasts for their humiliating defeats in the Tournament. After their loss, they gathered together on a hill expressed their anger and frustration at how powerless they were without Bit-Beasts of their own. The Dark Bladers shout towards the sky, asking for power to defeat the Beasts they despise. A transcendent being hears their pleas and decide to grant them their wish, provided the Dark Bladers give it their souls in exchange. They oblige and after being struck by lightning, they all become a different type of monster. Not only that, they develop supernatural powers and their Beyblades were infused with the powers of evil Bit-Beasts.
The Bladebreakers eventually find out that: Sanguinex had faced off against Robert Jürgens; Lupinex had faced off against Johnny McGregor; Cenotaph had faced off against Enrique and Zomb had faced off against Oliver in the Tournament.
In the present day, the battle begins but without Kai, the odds are stacked against the Bladebreakers. Meanwhile, Kai is practicing with his new Beyblade, Dranzer F, when he notices a bright light emanating from the Eiffel Tower and deduces it's the Dark Bladers. Finally, Kai shows up with his newly modified Dranzer and, as Oliver watches from the shadows, defeats Lupinex. Tyson then defeats Zomb, Max defeats Sanguinex and Ray defeats Cenotaph. The Dark Bladers phase out after their loss to the Bladebreakers.
While Tyson was exploring the Olympia Colosseum before the Olympia Challenge began, he picks up a rug that turns out to be Sanguinex's cloak. He tells Tyson that whoever wins the battle will be the Dark Bladers' prey. He mentions that their curse will disappear if they defeat the strongest Bit-Beasts in the World. Tyson attacks Sanguinex with a broom but he disappears. After exchanging some trash-talk with the Majestics, Kenny yells out encouragement. Tyson realizes he's not on the team bench and look up into the crowd, where he is sitting with the Dark Bladers. Tyson accuses them of kidnapping him again but Sanguinex says that they are just going to watch the battle (Personal Monster Cheering Squad in the Dub). The Majestics notice them as well but Robert's words indicate that he refuses to remember them, riling them up and scaring Kenny in the process. While Tyson is battling Robert, Sanguinex realizes that even though the Majestics and the Bladebreakers both have Bit-Beasts, they are distinctly different teams. Kenny explains that the Bladebreakers are different because they fight with their friends. When Johnny is about the interfere with their battle, the Dark Bladers stop him using Sarcophalon. After the battle, the Dark Bladers challenge, not the Bladebreakers like they originally planned, but the Majestics instead. Sanguinex explains that they will only direct their anger towards Bladers that do not treat others or their Beyblades with respect from now on. After Robert agrees to the challenge and apologizes for turning them into monsters, now remembering who they are, the Dark Bladers realize that the Majestics have changed for the better. Sanguinex thanks the Bladebreakers and smiles for the first time. After the battle, they are seen outside the Stadium with the Majestics and Bladebreakers discussing the future.
In Final Showdown, the Dark Bladers watch Tyson's final battle with Tala. When Judy implores the remaining Bladers with Bit-Beasts to be ready for battle in case Tyson loses, Michael notices that everyone in the audience is smiling. They wonder why when the Dark Bladers walk up behind them and explain that they feel Tyson's love and passion for Beyblading. Enrique asks them if they've been watching the whole time and Sanguinex answers that since Tyson is battling, they wouldn't dare miss it. After the Finals, the Dark Bladers challenge Tyson, along with everyone else, to a battle.
Sanguinex and Lupinex only appear in the Special Japanese Ending. They are seen grinning and standing across from Johnny McGregor, Enrique, Miguel and Claude. Lupinex's face is obscured but his wide smirk and hairy wrists are telltale signs that it's him.
- The Dark Bladers all have Bit-Beasts with names suffixed with -lor.
- The Dark Bladers' Beyblades are modeled after their Bit-Beasts and their Bit-Beasts appear with a certain part of their body shaped like an attack ring.
- Every battle that the Dark Bladers had were all losses, apart from the trap Cenotaph created for the Bladebreakers, which didn't have an outcome.
- They and their Bit-beasts are all based on old cinema monsters; Dracula, the werewolf, the Mummy and Frankenstein's monster.
- Their bit-beasts bare the weaknesses of their counterparts, for example Lupinex's werewolf bit-beast is weak to silver while Sanguinex's is weak to both daylight and a cross.
- The Dark Bladers are the only "filler" team with Bit-beasts in the original season. They are also one of the only 2 teams not to appear in the associated video games between 2001 and 2002, the other being the duo of King & Queen.