User blog comment:Blaziken rjcf/Why God created the Leviathans/@comment-26271908-20160615014435

I would not stick with the theory he created them in Amara's image like he did create the Humans in his own. After all, if they were to be like her, them he would know he was creating all-devouring, universe-destroying creature, who goes against his original wish to create (Remember that it was not until Lilith's creation and Lucifer's Fall that God decided he no longer wanted to be Lord)

I would say that he created Leviathans as a prototype to Humanity, because he wanted a perfectly normal race to populate Earth, but then he noted that Leviathans were not exactly what they should be and locked them away. The Bone Weapon is the greater mistery that we need to fit in. To put it in the timeline, then it must be after the creation of demons, because it needed the blood of the King of Hell to work. That is also the fact they are older than Angels, but all Angels were existing by this time. It is possible to say that Leviathans evolved with Humans and just became a real threat after humanity was fully developed and Lilith was twisted into a White-Eyed Demon, and that their evolutionary process began before the creation of the Angels, and only after their first evolutionary step was done the Angels were created... This part of timeline is just too confuse

And, sorry, but I can't see the similarities between the method they found to defeat her in We Happy Few and the Bone Weapon. Sure, demons and angels are inside it, but what the weapon needs is specifically the blood of a Fallen Angel. The fact that all Angels are Fallen by the current status of the series is just a coincidence to this