This episode aired in April 18, 2009.
The Next battle with Eradicus has come at last! Unfortunately for Yin and Yang, the parents of their Woo Foo Army refuse to let their kids fight! Even worse, Eradicus has learned from a captured Master Yo the darkest secret of Woo Foo: The Woo Foo Aura Drain! And he has used it to zap Yin of her aura! The only cure is an Aura Transfusion from a parent (or children which Yin and Yang do not have)! Now, Yang's sword must guide Yin and Yang to their long-lost parents before Yin vanishes from existence while Eradicus's forces decimate their defenseless town! Who are Yin & Yang's parents? Will their army be allowed to fight? Will Eradicus be defeated for good, or is the world doomed to become a modernless wasteland filled with Eradicus's accordion-based terror?!
As Eradicus initiates his final assault on the town, the Woo Foo Army is prevented from fighting by their respective families. To make matters even worse, Yin's Aura is completely drained by him! The only known cure for an Aura Drain is having an aura donor, which must be a parent.
With this realization, Yin and Yang begin a search for the parents they've never known, only to be led into a trap and subsequently imprisoned in Eradicus's cave by Yang's Sword. There, they find Master Yo unconscious. However it seems Yang's sword has not misguided them. Unknowingly, Yang transfers part of his aura into Yo's body, who in turn saves Yin. Both are dumbfounded by the scenario. But then Yo explains that he is Yin and Yang's biological father after catching a glimpse of his life so far (the "Edge of Aliveatude") in his stasis state.
Yin, Yang and Yo then finally make their escape from their holding cell and immediately hurry to the town to engage in one next battle against Eradicus! But even with their Auras combined, the tide of the battle is still tipped to Eradicus' faovr. In a remarkable turn of events, all the members of The Woo Foo Army have been given permission by their parents to fight Eradicus and his Army. The entire Woo Foo army then lend their Woo Foo Energies, resulting into an Aura of even greater size and power! With the combined efforts of Yin, Yang, Yo and their army, Eradicus is finally defeated and he, his minions and his army are banished into a dimensional vortex, the same fate of the Night Master since Night Fall.
After, a montage is presented, showcasing the Woo Foo practitioners regarded for their heroism and continue carrying out their heroic actions. Yin and Yang are also officially declared Level 2 Woo Foo Knights, leaving them to question Yo on who their mother is. The episode ends with a new villain, Ferocitus, introduced, and Yin, Yang and Master Yo yelling out their battle cry - "Yin! Yang! Yo! Let's go!" - as they face this new villains Just Begun
Eradicus and his minions
Woo Foo Weapons Introduced
Woo Foo Techniques Introduced
- This episode is the season finale for Yin Yang Yo! season 2 as well as the series finale since the series was suddenly cancelled.
- In this episode the identity of Yin and Yang's father has been revealed: it appears that Master Yo was the biological father of Yin and Yang the whole time and that he couldn't remember due to Masters Ti and Chai having erased Yo's memories in order for him to train them unbiasedly without worry for their safety.
- Ultimoose is declared as a threat to himself, not to society.
- Lina, Roger Jr., Dave, Coop, Jobeaux and the rest of the members of the Woo Foo army become Woo Foo knights and are meritted for their heroism against Eradicus.
- According to the show's creator Bob Boyle, Yin Yang Yo! would return for a third season On Nickelodeon sometime in 2010, with Ferocitus as the possible main antagonist. However, due Jetix's departure from the TV and the appearance of Disney XD, the show was sadly cancelled.
- This episode appears to have demonstrated family-genre themes the most in the entire series.