>>723606404
>to this day I still don't fully understand the whole ending
So here's the ending as I understand it.
Remember that time Klaus pushed the button and split the universe in 2? Well it turns out anime magic doesn't have shit on gravity. Because the 2 universes began to become gravitationally attracted to one another. And because both have differing forms of matter, the most likely result is that both will fucking explode when they touch. Well that's fucking frightening. So before the 2 universes touch, the 2 leaders of Keves and Agnias, Melia and Nia, called each other. And together they worked out how to make a machine that can offer some hope: The Origin. They don't say Tora made it, but Nia mentions that a Nopon helped her so of course it was Tora. Going inside the Origin you see thousands of Core Crystals and you realize what they did. They repurposed the natural function of the Core Crystals. The same way they would record information on life for The Architect to monitor, the Origin would record the data on all of existence, so that when the universe blows up, The Origin can survive and restore life as it was.
Why did I establish all that? Well apparently all the lives that The Origin recorded collectively agreed that they want things to stay as they are right now. So when the universes began to touch, The Origin stopped everything. And invented the character of Z to keep everything halted. The goal of the ending is to fix Tora's broken machine, allowing time to process to the literal apocalypse of the universe, so that The Origin can do its job and remake all life after the end of time and space. The remade Noah can live his life without ever knowing that he'd been trapped in a cyclical hell of dying and being recreated over and over again and that they live in the ashes of 2 dead universes.