This is how Aqua and friends see Mickey and heading to Destiny Island in Ryan's Quest: Birth By Sleep 0.2: A Fragmentary Passage.
Aqua, Stewie and Brian are falling into the Darkness
Brian: Roxas... Ryan... We're sorry.
Stewie: Meg... Peter... Lois... Chris... Looks like it's the end for us.
Aqua: Now, we can be... one with Darkness.
Her Wayfinder has slipped off of her hand and it was been grab by something
????: Aqua, are you okay?
It was Mickey and he take them to the ground
Aqua: Mickey, how did- Terra! Ven!
Brian: Thomas! Tino!
Mickey: No time to talk.
Aqua: Dweller of Darkness...
Mickey: They're called Heartless.
They are fighting them and they defeated them
Mickey: Better not push our luck. Gosh, I never thought find you and your new friends in the realm of Darkness, that's for sure. So, um, what happen?
Aqua: Have you seen Terra and Ven?
Brian: Have you seen Tino and Thomas?
Mickey: No, just you and your new friends.
Aqua: We're sorry. The Darkness in this place it's getting to us.
Mickey: Oh. but, you'll be okay.
Mickey: Say, we've been looking for ya a long time. How come you're in this place?
Aqua: First, tell me, Brian and Stewie: How long's it been in the realm of light.
Mickey: About... Ten Years.
Brian: 10 years!?
Aqua: Interesting... After we last spoke, I took Ven somewhere safe, and then I went after Terra. But Terra was about to fall to Darkness, so I have one choice. I'd stay here in hopes of giving him a chance.
Mickey: And you?
Brian: Me and Stewie went off finding our friend that the bad guy possessed him. And then our friend was about to fall to Darkness. So me and Stewie have one choice, we stayed here in hopes of making him fight for us.
Mickey: I... didn't know.
Aqua: How about you? What could've brought you here? Has something happened? In the Realm of Light.
Mickey: It's the Heartless. They've been attacking worlds and taking their hearts. And world's with no hearts vanish into Darkness. But if we can lock the door between the two realms- light and dark- from both sides, we can protect the other worlds. And you know, we came here to find the key on this side. Turns out, it's not so easy getting into the realm of Darkness. The point you can cross have been unstable. It's only when a world gets consumed, that an entrance appears in the realm between. So, waited my chance... To sneak in. But hey, when I got here. I felt three warm, familiar light. I follow it to find my way to you and your friends.
Aqua: The Charm. So they were helping Terra and Ven brought you and us back together again.
Brian: But, the world's are still in danger.
Aqua: Terra- did he make it back to the realm of light?
Mickey: We still haven't found him.
Aqua: I see..
Stewie: But, don't worry. Wherever he is, he's fighting. He'll defeat his Darkness. And we know, that he wants us to fight too.
Mickey: I thini, you're right. He'll be just fine.
Aqua: Yes, but what about Ven? He won't wake up unless I'm there with him.
Brian: We have to go. We have to find way back to the realm of Light.
Mickey: Good. Then let's locate that Key and go home together!
Brian: You found a way out?
Mickey: Well... Uh.. I was so busy finding the way in, that I didn't give a lot of thought to where there'd be a way out. But, together we're sure to find one!
Aqua: You haven't change at all.
Mickey: May our Hearts be our guiding key.
Brian: Hey, I know that word.
Aqua: There's a phrase that no one's use in ages.
Mickey: Keyblade, Digidestined, Digimon and Warrior Wielders used to say those words to each other. And now, it's something I like to try and remember. So, ready?
They arrived in Destiny Island
Brian: Where are we?
Aqua: This is... where I met those children.
Mickeu: So many worlds have been lost. And now, they're here in the dark. Wait, you know this place, Aqua, even you two?
Aqua: Yes. I visited once, and I met two boys I considered passing the Keyblade on to. But because Terra had already given one of them the power, I didn't.
Mickey: You two?
Brian: Me and Stewie been here once. When our friends return to this world after the battle.
Mickey: Aqua, Brian, Stewie. What are the boys names.
Brian: Their names are...
Aqua: They were... Sora and Riku.
Mickey: I see. We're getting warm.
Mickey: Welp, it's Sora and Riku who've been helpful me. We're trying to get that door shut for good.
All: The same boys?
Mickey: Aqua, Brian, Stewie. If this where my friends first got the Keyblade it also must be where we'll find it's counterpart. The Keyblade of Darkness has gotta be here on the dark side of their world.
Then world is shaking
Mickey: We'll have to hurry, come on!
They are fighting the Swarm of Heartless and they defeated
Mickey: Let's keep going.
They went to the Secret Place.
Mickey: I bet it's in here.
They saw the Keyblade
Brian: Is this what you're looking for?
Mickey: Yep, it's just the key I was looking for. The Keyblade of the dark realm.
Aqua: The Keyblade of Darkness.
He grab it
Mickey: "The Door of darkness... Tied by two keys. The door of Darkness... To seal the light? Welp, we've got the keys. Now, we find the ones to close the door.
Mickey: The Door between the two realms- it won't let a heart of light pass through. So only Darkness keeps slipping out. We can lock the door by using the two Keyblades, but we need help on both sides to get the door shut.
Aqua: Well, then, since you'll be doing the locking let us be the one to close the door.
Mickey: Sorry, but the job's taken... by somebody else.
Then light appeared, Riku is wondering around in the Darkness and they saw the door
Aqua: Is that the one?
Mickey: Yep, the door to Kingdom Hearts. Welp, it's not the Kingdom Hearts you know. Not exactly. But even though it's smaller, it's still the heart of many worlds. And even, it's not a complete Kingdom Hearts, we definitely can't leave it open like this, or Darkness will escape and destroy the remaining worlds. It's time. With this Key and Sora's in the realm of light, we're gonna close this door. Now, all we need is Riku.
All: Sora... Riku...
Mickey: Over there!
They saw Riku running to the Door
Mickey: That's everybody, let's go, Aqua, Brian and Stewie!
Then Swarm of Heartless is heading to Riku
Mickeu: Oh no!
They are gonna stop them
Aqua: Back off!
She chained them and she, Brian and Stewie can't on much longer
Mickey: Aqua! Brian! Stewie!
Aqua: Go without us!
Stewie: Do this without us!
Mickey: No, I--
Then the Heartless has been loose and it got Aqua and her friends and it's heading to the Door
Mickey: Aqua! Brian! Stewie!
Aqua and her friends are fighting the Heartless
Brian: The battle for the realm of light.... is not won.
Aqua: Thanks to Terra and Mickey, we know what's at stake.
Stewie: We're not afraid, we will face the long Darkness.
Aqua: The Next time someone wonders in the realm of Darkness. We'll be there.
Brian: A light to cut through all the shadows. We will be in their Wayfinder.
Aqua: And One day, we will return to Ven and Terra. I am Master Aqua.
Brian: Names Brian Griffin. Batman Brian.
Stewie: I'm Stewie Griffin. Iron Stewie.
All: And that's a Promise.
Mickey: Aqua... Brian... Stewie...
He have to seal the Door to Darkness
Mickey: Now, Sora! Let's close this door for good!