Oh boy. Where to start? Well, let's just say that I'm all for mixing genres. But that does not give people leave to throw in everything and the kitchen sink and think it will be good.
In Master of Dragons by Angela Knight, Nineva Morrow--an orphaned fairy princess and avatar for a goddess trapped in a sword--must work with a shape-shifting dragon named Kel to thwart some power-hungry fae and evil demon aliens from taking over and possibly destroying the Mageverse. To save the universe Nineva and Kel must have (frequent) sex which will supposedly feed power to the goddess and free her from that pesky sword. Obviously, this isn't particularly a hardship for the characters, except Nineva keeps having dreams that Kel will fry her to a crisp.
I'm not against plots hinging on sex especially in an erotic romance, but in this book, it only serves as mere titillation. There's no chemistry between the characters. And they weren't particularly smart or logical either--if the goddess needed to be powered by sex magic, couldn't they have just invited a bunch of people for a huge orgy and have it done with rather than prolonging the agony with two characters who go at it like robots?
And don't get me started on the world building. To say the least, it's sloppy. It's confusing and complex in a not good way--like having someone playing a terrible prank at the UN by swapping all the placards and translators while having the agenda being argued over by Japanese girls in Lolita costumes and Trekkies fluent in Klingon. Not only are there prophecies, fairies, and dragons--but also demons, King Arthur and his court, vampires, werewolves, deities, trans-dimensional alien travelers, mages, talking books...well, pretty much everything except superheroes in tights.
Frankly, Master of Dragons is a blight on both fantasy and erotic romance. If you want a successful blend of the two genres, go read Emma Holly instead.