Although I just read it today the characters just feel a little too not worked on, I'm a fan of Greek Mythology so it's a subject I get sensitive about and it felt wrong in a sense. Artemis isn't necessarily the Goddess of the Moon, she's just one of them, she's more Goddess of the hunt, forests, hills, archery, and moon; not just the moon but others. When I hear the name Artemis I instantly think "Hunt" since her stories are told mostly about her gift of hunt with a skilled bow and the fact she has a twin, Apollo God of the Sun. Moon never comes to mind, I know there are times to give offerings during certain moon phases, but other then that she's not solely the moon. Also Hecate isn't the Goddess of the dark moon... That's the part that made me laugh because the author did keep her 'dogs' but she's mostly the Goddess of Magic, Crossroads, Ghosts, and Necromancy; more like a witch that is a God if you look at it, plus she resides in the underworld lol.
The one I know as the Goddess of the Moon is Selene, she much like Zeus was born from Titian parents, but her siblings are also the Sun God Helios, and the Goddess of Dawn Eos. Their names all translate out to Moon (Selene), Sun (Helios), and Dawn (Eos) in Greek, plus Selene resides in the sky and rides a Moon chariot lol. And there is nothing else that she is the Goddess of besides the moon.
If we go back to the Hecate bit the only way she can represent the moon is when there are three of her. "Triple Hecate was the goddess of the moon with three forms: Selene the Moon in heaven, Artemis the Huntress on earth, and Persephone the Destroyer in the underworld." So if we look at it this way, Hecate is made up of 3 Goddesses, not just one. The author didn't quite do all her research before jumping into this one.
It's slowly getting better, once you get past that volume I don't see an issue any longer. Looks like the climax is nearing to o-o