The Fallen Angel

As a child is born, the creature within grows alongside; werewolves with their wolves, mermaids with their aquatic talent, witches with their power and vampires with their over heightened senses. Lucas Wolfe knew from the very beginning who he was,the son of the head alpha pack in Canada. Being next in line to the title, he had everything he ever wanted. Well, except for one thing: a mate. When he couldn't find his mate after he turned 18, he became hopeless and moved on. With his parents eager for him to lead the pack, they arranged him to be with Luna Adriano, the daughter of the head alpha of the creatures. Only issue is, she's been dead for 13 years.
How can Lucas be mated to a girl that died, unless they mean dead in a different way....