I believe what Heriod77777 is bringing up is the explanation we get from OoT, not LttP:
http://forums.legendsalliance.com/t...ame-texts/page__st__90__p__374456#entry374456
Translation of Japanese Game Texts - Legends Alliance Forums - Page 4 said:
聖なる三角の在るところ… 聖地は己の心を映す鏡なり。
The place where the sacred triangle is, the Sacred Realm, is a mirror that reflects one's heart.
The resting place of the sacred triangle, the Sacred Realm, is a mirror that reflects what is in the heart...
そこに 足踏み入れし者の心、邪悪なれば 魔界と化し、清らかなれば 楽園となる。
If the heart of one who enters it is evil, it turns into a Makai [Demon World]; if the heart is pure, it turns into a paradise.
the heart of one who enters it... If an evil heart, the Realm will become full of evil; if pure, the Realm will become a paradise.
魔界, or Makai, is generally what we consider the Dark World when brought up in reference.
And then in WW we get from the King of Red Lions:
http://forums.legendsalliance.com/t...me-texts/page__st__780__p__404258#entry404258
Translation of Japanese Game Texts - Legends Alliance Forums - Page 27 said:
ヤツの名は ガノンドロフ
His name is Ganondorf.
His name is...Ganon...
神の力を手に入れ、世界を暗黒の魔界へ 変えようと企み、神の力によって封印された
He obtained the power of the gods, planned on transforming the world into a Makai of darkness, and was sealed by the power of the gods.
...He who obtained the power of the gods, attempted to cover the land in darkness, and was ultimately sealed away by the very power he hoped to command.
いにしえの伝説にある魔界の帝王 それが、あのガノンドロフなのだ
The emperor of the Makai in the ancient legend is that Ganondorf.
He is the very same Ganon... The emperor of the dark realm the ancient legends speak of...
神の封印がなぜ解かれたのか わからぬが 彼奴が蘇った今、再び、世界は邪悪な魔力に 脅かされ始めているのだ
I do not know why the gods’ seal has broken, but, now that he has been revived, the world has once again begun to be threatened by his evil magical powers.
I do not know why the seal of the gods has failed, but now that Ganon has returned, the world is once again being threatened by his evil magic.
That is to say, in WW, the Dark World was vaguely referenced, but called the Dark Realm instead in translation. But since WW is talking about the adult events of OoT, it is safe to say that the Dark Realm that the King of Red Lions is talking about is the Sacred Realm that Ganondorf was sealed up in, which would make sense, since WW is a sequel to OoT. How LttP relates to WW is unclear, though the two aren't likely sequel or prequel to each other, so LttP's explanation of the Dark World doesn't really play into WW or ST.
But continuing on, the Dark Realm is talked about a lot in ST as where Malladus and the Demon Train come from, and since ST is a sequel to WW it probably is talking about the same Dark Realm.
Byrne said:
The Demon Train comes from the Dark Realm. But even Cole didn't know its exact location at first. He had me build a compass using the spirits' power to find the Demon Train in the Dark Realm.
ST Princess Zelda said:
This is the nest of evil, the Dark Realm. Cole is lurking here...somewhere.
It is through all this that I think Heriod77777 is talking about in his original post. In OoT it says that the Sacred Realm turned evil because of Ganondorf's evil heart; in WW the evil Sacred Realm that Ganondorf was said to have been emperor of was translated as the Dark Realm; and in ST Chancellor Cole is involved with and Malladus and the Demon Train are said to have come from the Dark Realm.