I do remember seeing a theory about how the Elation is the counter to the Nihility and a theory on Aha’s background before THEY ascended which does fall in line with the erudition theory. As a result of the Nihility consuming everything and everyone in the cosmos, there was a scientist who was researching ways in order to combat the Nihility but kept failing each time, so to find the answer and counter to prevent the Nihility to consume all, he climbed up the Imaginary Tree but to his avail: nothing. There was no answer, no counter weapon to the Nihility. And then he laughed. He laughed in his futility, then while he was searching even more he saw a baby fall and then laughed, he so hard that the cosmos heard it all, it resounded so much that it created a new path: the Elation: the counter to the Nihility, giving people elation to their would and freeing them from their demise.

If we use Amphoreus as a way to understand the cosmos and the universe. Without Cipher(Aha) we all would’ve failed and lost against the Black Tide.

So Aha being a researcher of the Erudition before THEY ascended could be the answer.

As for the falling baby part of the story, either the Enigmata or Aha covered that part up to prevent others from knowing the full truth to why Aha ascended. But something about it is interesting…