How were the worlds restored?

[spirit-of-light]

I've always wondered exactly how beating Ansem and closing the Door to Darkness restored the worlds. I can understand how closing the door would make the walls come back up, but how did that bring back all the worlds that were taken by the heartless (at least the ones that didn't go to sleep)?

 

[Dandelion]

It's possible that defeating Ansem is what triggered his false Kingdom Hearts to be destroyed, and in effect reversed the damage - similar to how defeating Xemnas destroyed his Kingdom Hearts and restored all those people from being Heartless

 

[drumstickwielder]

Since I don't know how far you've gone in the series, spoilers for the most secret ending of birth by sleep final mix. After Aqua roams around in the realm of darkness, she finds a world she's visited, one that we know (from Kingdom Hearts 1) fell to darkness, and that world is Castle of Dreams. From this we can infer that worlds that fall to darkness simply move from the realm of light to the realm of darkness. If a person were unaware of the RoD and a world fell, to them it would stop existing, when it really just moved. So at the end of KH1, the worlds restore because the move to the RoL from the RoD (aside from the sleeping worlds, I couldn't explain them if I tried).

 

[berrybob]

If anyone is wondering how Roxas and the Organization Xiii did teleport to other worlds even with those impassable walls, it´s probably because the darkness is a way to pass those walls. Probably related to what drumstickwielder (the person before me) said.

Edit: Probably it tells how Xehanort could do his plan. He could even sacrifice his body to gain the power of time travel! All this to get flexibility in making his great plan of getting Kingdom Hearts.

 

[Anagram]

Like the wise Ruran once said; "ending magic".