Here is how Yuna and her comrades defeat the villains and Mission accomplished goes in Candace and Stacy's time with Sebeena.
At the Villains' hideout.
Bowser: We will not tolerate this!
Dr. Eggman: You cannot win!
Perry the Platypus/Agent P: (winks at Yuna)
Princess Yuna: We already have, Dr. Eggman! (opens the portal to Tartarus)
Sonic the Hedgehog: Say Hi ti Tirek for us!
Then, the heroes defeated the villains.
Bowser: No... no... Curse you! CURSE YOU, YUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUNNNNNNNNNNNNNAAAAAAAAAAAAAAAAAAA!!!!!!!!!!!!!!!!!!!
Princess Yuna: That went well.
Heinz Doofenmirtz: I'll say, Princes Yuna. Well, Love to stay and chat. But I better get back home. Catch you later, Princess Yuna. See ya, Perry the Platypus.
Major Monogram: Job well done, Princess Yuna.
Carl: Same goes for you, Sonic and the Mario Bros, Agent P.
Perry the Platypus/Agent P: (nods and thumbs up on Yuna)
Princess Yuna: Glad to help, Perry.