QUOTE(mirocu @ Dec 1 2016, 08:54 PM)

That's not something I recognize. Accounts may vary but I've never come across that one. The only one I've heard is about the new world starting up (an event called Ragnarok) and in order for that to happen "the old" must be destroyed. Nothing about "enough" destruction, just destruction, in which the old gods, trolls and monsters fight and die and the old world is destroyed in order to leave room for the new.
The balance of powers sound more like the old world where the gods constantly had to balance the chaos created by the trolls.
Destruction, yes, but not
complete destruction. Elements of the old world survive into the new one, even some of the gods survive or are resurrected. So some of the old world was preserved, but not enough to keep things the way they were. And consider the fighting itself:
The greatest weapons of the Aesir; Mjolnir and Gungnir, to say nothing of their wielders. And they're each met by a monster that slays them, though the monster in turn is slain. Denying all of them any impact of events beyond their personal battles. And in the case of Thor and Jormungand, we see the perfect neutralisation of forces as the two slay each other.
It's not explicitly stated, but the elements are there.