A few questions

[Avens]

The world of darkness, and Ansem's shadow, still nest within your
heart. Do you plan to face Sora like that? Are you not ashamed?

In the original, he just says 'darkness'. Is this a translation error or something more? I have no clue, and the only thing I can think of is that's the name of Ansem's guardian Heartless, since the final boss in KH is World of Chaos.

And secondly,

Riku: But...uh, how did you make it here? I thought it was too far.

Mickey: I found a card to help me.

(He takes out a card of Twilight Town)

Mickey: I needed a way outta the realm of darkness, and then suddenly, this
card appeared right in front of me. When I picked it up, I could see your
heart beyond the darkness. That's what let me find you. I guess the card
thought its place was to be with you.

Was that ever explained, or is this DiZ playing around?