Read my above post. a)How do we know that they are sealed? Yes, there is certainly a barrier between the worlds, but Hylians are as much sealed in their world as the Twili are in theirs. b) Maybe they didn't need to banish them at all; again, there is nothing in the game to suggest that the Goddesses did anything to the interlopers themselves, only that their power was sealed in the fused shadows. So, no, the Goddesses did not banish them to the sacred realm, they only took away their powers so that they could cause no trouble their. See?

Oh, so that is definitive proof, eh? There couldn't possibly be two entrances, could their?! Considering their are already a whole host of other entrances scattered around the world in AlttP, aren’t there. Also, to my knowledge (though I may be wrong) the only reason that there was a portal at Hyrule Castle was that was the first place Agahnim first broke through, creating a rift their.

I am fairly certain that there is nothing in the game tha suggests that the Twilight Realm isn't the sacred realm. I get the feeling it was supposed to be obvious in the first place, but maybe things got lost in translation.