Hiya, thanks for the ask! :D

(a little context, this is lore for an oc universe that includes Mika, Francis, Hanah, etc.) Azura and Wormwood are full of god-parasites, hive-minded entities that infect gods to feed on their divine energy. The Moth and the Worm respectively inhabit them.

As for their beef with Mika, Azura and Mika fill a similar niche, in that they both hunt and kill gods for their energy, and they both like to try to bite each other whenever they cross paths. Wormwood on the other hand, has a more personal hatred of Mika. Her only child is being stolen by the cult of the Red Star, dedicated to worshiping them. As you’d expect, Mika is delighted by this.

Aether, also known as giant’s blood, god’s blood, or sometimes quintessence, is a formless, superphysical substance and integral part of life for people in Balor. It is mined out from the colossal corpse of a dead giant whose skull rises over the city, and whose flesh-like remains lay beneath it. Below are concepts for how aether is mined.

 Pure aether (below) is extremely volatile and is contained by specialized materials, except for in specific laboratory settings.

While people like Regan (freak) can integrate it into their bodies, the majority of aether is used in infrastructure, a large circulatory system embedded into the city that keeps it functioning; like keeping railways operational (below) and heating the city to keep it from freezing over, among other things.

As for how someone can get their little freak hands on it, there are legal ways of doing this, and it helps to work at the corporation that monopolizes aether engineering. Although Regan got her spectrals as a result of a DIY bathtub infusion in grad school that she orchestrated all by herself :)