Here is how Equestria and other worlds were saved in Princess Yuna's Adventure Begins.
So, Yuna and her friends begin to stop Armageddon.
Princess Yuna: Alright, Everypony! Hold on to me!
Rainbow Chakra: Are you even sure about this, Yuna!?
Princess Yuna: It's our only chance of saving all the worlds, Rianbow Chakra!
Yuna cast a spell as the others work their energy for her to end Doomsday.
Princess Luna: Is that Yuna?
Princess Celestia: She made it!
Princess Cadance: And save Equestria and the other worlds!
Twilight Sparkle: She did it!
Trixie: And not a moment too soon!
Sunset Shimmer: And how!
Princess Yuna: Well, That wasn't easy.
Train: (whistles) We won!
Oh: We made it!
Prince Edmond: We all did, Oh!
Oh: We owe it all to Yuna!
Princess Yuna: It was nothing.
Dusty Crophopper: You did it!
Princess Yuna: No. We did it together.
Dusty Crophopper: Yeah, We did.