The opening quarter is quite interesting, but at the appearance of the sex...sorry.. dark Gods, the novel turns into one long sex (or rape) scene after another. Effectively the main character can't make it through a chapter without being in a sex scene or without being a threatened with rape.
The main male character should be called, Captain 'my backstory makes me a dick' Exposition and Aislinn turns into the most ludicrous Mary Sue I've seen in a while. She goes from being reasonably talented in some forms of magic to being the 'Chosen One' because 'Celtic Myth says so'. And I really couldn't get behind the 'relationship' between the main characters as it basically boils down to 'wow you get me soooo hot.. bang me some more' And I couldn't for the life of my work out why the aliens were there, they just were because apparently evil sex gods weren't enough of a threat.
Well written book with a decent premise and some great characters, unfortunately let down by some really weird plotting.