The Horn

[Alice_89th]

...Or Asciens are the one's responsible for making these "Keys" since Elidibus seem to want to forge the "final key"

He seems to be refering to

us, the WoL. That dialogue made it sound like we somehow need to become stronger and thus become the final 'key' to summoning/awakening Zodiark.

We've just learned from the WoD that too much light can also cause a calamity (or worse) so that may very well be exactly what Elidibus was/is planning: to make sure the WoL is so powerful that they upset the balance and thus cause a calamity.