[Bafflebox]

Awesomecakes! And thank you so much~! <3
The evil~ Hm~
Perhaps there are two realms within the Indigo World, or more specifically a division among the Indigo people. I wouldn't like to restrict myself to having just two countries; not only because it sounds uninteresting, but it also sounds very unrealistic.

As for the world itself, I imagined it to be lit as if there were a purple light shining over everything - you know, perpetual twilight, rather than the world itself actually being all purple. Perhaps the purple hue of the sky is affected by the magical alignment chosen by the majority of the inhabitants or whatnot; the character approaching the girl, I think, should be a non-humanoid creature. Not that it should become a fable, but very fantastic, still. :)

It's magical in itself that she has stepped into the Indigo World, so perhaps her presence is simply noticed by creatures in the vicinity - that would also explain any creatures in the vicinity, save for that trickster. Her hanging out with a widely known trickster would immediately affirm to the locals that she's bad news, as people all over the world will assume when something new appears. :)

The wall, I think, should serve as a blockade for her to travel back on a whim. You know, "One does not simply walk into Mordor," and all that fun stuff~! So, I think the creature seeks her out after having sensed her magical presense. Or something. I don't know, does this even sound like anything plausible at all?