This is the scene where Ash and Serena encounters Master Xehanort in Ash and Serena's Great Adventure.
(Later Ash, Pikachu and Serena are now by themselves walking in the closed deserted carnival)
Ash Ketchum: Serena, we did it.
Serena: Yeah, we finally got four pieces of the heart jewel and now we're going to put the pieces together.
Ash Ketchum: Yeah, I can't wait for that.
(Then suddenly a slow clap hands noise came out of nowhere as Ash, Pikachu and Serena turn their heads to the right side they see Master Xehanort while he does the slow clap)
Ash & Serena: Master Xehanort!
Xehanort: That's correct.
Ash Ketchum: What are you doing here?
Xehanort: For the pieces of the Heart Jewel. So I can find the X-blade and one day rule the world.
Ash Ketchum: Not gonna happen!
Serena: Not on our watch!
Xehanort: We shall see.
(Ash and Serena are about to throw their Pokeballs but Xehanort brings out Heartless and tackles them)
Ash Ketchum: Get off of me!
(Ash reaches the keyblade and stabs the heartless and stabs another one that was attacking Serena)
Serena: (Breaths in relief) Thanks.
Ash Ketchum: Enough, Xehanort! We already have the pieces of the Heart Jewel so just get out of here!
Pikachu: (Electricity appears out of his red cheeks) Pika! Pika!
Xehanort: Oh, that doesn't matter. (He shows them a Keyblade) I'll just use this.
Ash Ketchum: A Keyblade!
Serena: (Gasp in surprised)
(Xehanort aims the Keyblade at the four pieces of the heart jewel draining their powers and then turns the sky into darkness)
Xehanort: I use my Keyblade to drain the powers of the Heart Jewel that will make me unstoppable. (Opens a portal and walks in) And of course, the darkness in the sky will summon a massive army of Heartless and Nobodies. Ooh, I got to get back to my castle. I'll see you soon in my castle.
Ash Ketchum: Stop!
(Pikachu fires thunderbolt try to zap Xehanort but the portal closes and misses)
Serena: He's gone!
Ash Ketchum: We've got to warn everyone!
(Cut to the heroes look up in the sky seeing darkness around the city)
Tino Tonitini: Oh, my gosh!
Dr. Z: What in the name of dinosaurs is darkness doing here in the sky?
Clemont: But Ash and Serena, already collect four pieces of the heart jewel.
Skips: Well are you sure?
Tino, Lor, Carver and Tish: Yes!
Tai Kamiya: Of course they did manage to collect four pieces of the heart jewel!
Sunset Shimmer: Then what is the darkness doing here?!
Matt Ishida: How should I know?!
Ash & Serena: Wait! Wait!
(They see Ash and Serena are exchausted from running)
Serena: We can't go!
Inuyasha: You two, what's going on?!
Ash Ketchum: Xehanort is here and he's drain the powers of the heart jewels and use its power to create a X-blade!
Tino Tonitini: Come on, Everybody. We've got to stop him and the Villains ASAP!
(Everyone runs and gets in Gummi Ship)