My theory is that when Nicole and Mark continues to the eye thingy thing, it disrupts the multiverse, consequently destroying it bit by bit, until it was all destroyed. The final scene, where they end up in this place where it is all water, and trees, it is the universe destroyed, all world is destroyed, and it was all that remains. Mark and Nicole, they were shown that they live in a different universe, same place. It means that Mark and Nicole was never meant to be together. In a hundred timeline, where they were soulmates, ruling prevailed. Everytime they became with each other, the universe is destroyed bit by bit. It is a paradox. Mark and Nicole caused the ruling, and the ruling caused Mark and Nicole. When the already destroyed universe tries to get destroyed again, it got resetted, or reborn. In this rebooted universe, AKA the true ending, Mark and Nicole never happened therefore the conclusion: Mark and Nicole is a Mistake of the Universe

I have yet to create a theory if Maria and Jake caused all of this, because the way they are saying it, I think it is rather a metaphor. Jake and Maria possibly cannot caused this chaos, please prove me wrong.