Hungry for a high grade aether
Every heart is a lair of a ferocious animal. The greatest wrong that you can put upon a man is to provoke him to let out his beast - Ambrose Bierce.
When the beast reveals itself to the outside world it does it through behaviour, surroundings and emotions. As for the Aoyin creature, it wasn't born this vicious. All it wanted was what rightfully belonged to it.
Like its ancestors, it expected human fear and sacrifices a few times a year which wasn't much to ask. It wasn't too demanding requesting for the simplest of things to spare millions. Eating five people a year to keep the rest of the population safe was a reasonable bargain in its eyes.
But apparently, some humans were reluctant hence they were forced by others who saw things the way the Aoyin creature did. This exchange was maintained for generations that is until the Nocru barged in from who knows where and took over.