This is how our Heroes went to Wizard of Oz world and how they stop the witch in Ryan's Quest.
Our Heroes made it to Wizard of Oz world
Sci-Ryan: Guys. I don't think we're in Kanses anymore.
Ryan: Let's go, look around.
They went off and they saw a Castle
Evil Ryan: This is pretty easy.
They saw a Witch
Witch: Looks like you can't find the Keyhole here.
Ryan: Let's go inside.
They went inside the Castle and they saw Dorothy and her friends surrounded by Heartless
Ryan: You have to hide.
They are fighting them and they defeated them
Ryan: Phew, that was close.
Dorothy: Thank you for saving us.
Ryan: You have make sure you and your friends be safe from the Heartless.
Dorothy: Heartless? Is that what you called?
Sci-Ryan: So what are you doing here?
Dorothy: Me and my friends are going to stop the witch.
Ryan: Should we help you stop her?
Dorothy: Yes, Please.
They went off and they found her
Witch: You're here! And nobody will stop me!
Crash: I think you got the wrong idea, lady. Ryan's got a Keyblade which means his skills in fighting Heartless are A-OK.
Witch: We'll see about that!
She summon her Heartless and they are gonna fight them, and they defeat them and the Witch is melting now
Witch: AAAHH You robot-brat! Look what you've done!? I'm melting! I'm melting! Oh what a world, what a world! Who would have thought a good robo-boy like you could have destroyed my beautiful wickedness? Oh! I'm going!
Ryan: Hee-hee. Now that's what I call a watery end.
Ryan saw the Keyhole, he seal it
Ryan: It's time for us to go.
Dorothy: Hope you can get back home soon like me.
Ryan: Yeah, bye!
Evil Ryan: How would that witch we beaten ever took a bath?
They left this world