Who's Your Daddy? (突然のサヨナラ..., A Sudden Goodbye... ) is the forty-first episode of Beyblade: V-Force.
The Bladebreakers show up at the World Championship Tournament and go up into the stands to cheer on Zeo who's fighting in the preliminaries. Tyson is pumped watching his new friend who wins his first fight. Later backstage, Tyson tells Zeo he's totally impressed and asks if Zeo would like to become his training partner. Zeo excitedly agrees.
Meanwhile, at Psykick's lab, Zagart finally finds out that Doctor K has been secretly extracting bit-beasts from the rock. Furious, he interrupts her research and fires her just as she is on the verge of removing the strongest bit-beast sealed in it. Zeo is shown arriving at his mansion, happy that he advanced to the next round at the World Championship. That night, he greets his father as he arrives, and it is revealed that the father is Zagart. Zeo is eager to tell him of his success at the tournament, but Zagart coldly sends him to his room and walks away.
Later, an angry Doctor K (accompanied by her main assistant) shows up to confront her former boss in his house and as she does, Zeo overhears the entire conversation. Zeo realizes it's his dad who's been after the Bladebreakers' Bit-Beasts and cries. As the argument continues, Zeo accidentally drops his Beyblade, alerting everyone of his presence. Doctor K leaves but not before telling Zagart of Zeo's partnership with Tyson and the others. Furious, Zagart grabs Zeo and puts him up against a wall, then drops him. Zagart explains to Zeo that he needs the power of the four bit-beasts and gives him Cerberus, the strongest bit-beast from the rock (the one Doctor K was about to extract before being fired), telling him that he must steal his friends' bit-beasts. Zeo asks him why, and Zagart explains, but that's not shown. Instead, the anime jumps to the point where Zeo is shocked by whatever his father just told him.
At the following day, the Bladebreakers' are worried about Zeo and are informed by his partner at the World Championship that he quit. He spends the whole day walking and reflecting about the secret he was just told and eventually comes upon the Bladebreakers. They try to confront him but he ends his friendship with them and leaves, crying. As he arrives home, he demands his father to give him Cerberus.
- Zeo is revealed to be Dr. Zagart's son.
- Dr. Zagart fires Doctor K for her actions.
- Dr. Zagart learns about Zeo's friendship with the Bladebreakers and tells Zeo more about himself.
- Zeo reluctantly tells the Bladebreakers that he can't join them and runs off.
- Zeo switches Beyblades from Zeronix to Burning Cerberus.
- Tyson Granger
- Kai Hiwatari
- Ray Kon
- Max Tate
- Hilary Tachibana
- Mr. Dickenson
- Zeo Zagart
- Tanner Conner
- Blader DJ
- Dr. Zagart
- Doctor K
- Mariam (video flashback)
- Master Dranzer
- Driger V2
- Dranzer V
- Dragoon V2 (video flashback)
- Draciel V (video flashback)
- Phantom Spider (video flashback)
- Sickle Weasel (video flashback)
- Tyranno (video flashback)
- Zeo Zagart (Zeronix) vs Tanner Conner's Partner (Generic Bey) = Zeo & Zeronix
- The part where Zagart grabs Zeo and puts him up against a wall and drops him is not shown in the English dub.