Elfin On the Run is the 35th episode of Bakugan: New Vestroia. It aired on January 9, 2010.
After Elfin overhears Preyas talking down about her receiving the energy and her rash behavior, Elfin runs off into the city and encounters Shadow Prove and Hydron before hearing the full conversation. Marucho and Preyas arrive in time to rescue her and a battle ensues. At first, Elfin and Preyas have trouble getting along, but they put their differences aside and almost defeat the Vexos, but Elfin shields Preyas from an attack, therefore losing the Aquos Energy. Preyas, out of anger for Elfin's sacrifice, easily defeats Hydron and Shadow Prove. After the battle, Dan, Shun, Ace and Baron fall asleep during the movie that they were watching (it was a movie for teenage girls that Runo, Julie and Mira wanted to see, but the boys were dragged there by the girls). Everyone else did not know Elfin lost the Aquos Energy. The Vexos only need 3 more Attribute Energies before they make the BT System fully functional.
- Hydron and Shadow arrive on Earth to look for the attribute energies.
- Marucho battles Shadow and Hydron and wins.
- Elfin is knocked out in the last round, losing the Aquos energy in the process, so Preyas secures the victory for Marucho.
Bakugan Trap Seen
- A scene of Hydron being surrounded and admired by three schoolgirls was cut in the English version. That scene was in the Japanese version after Shadow Prove scares off an old man asking for directions and complains about the police outfit he was wearing.
- The old man who asks Shadow directions was voiced by Keiji Fujiwara, Drago's Japanese voice actor in the Japanese dub.
- This is the only episode where the Battle Brawlers won the battle even though the Attribute Energy was taken.
- When the computerized voice reads out Marucho's life gauge after the end of the first round, it claims he has 30% of his points left, when in fact he has 40%. Later, when Elfin is defeated, the voice claims that Marucho's life drops to 10%, when in fact it is 20%.