Under a Blood Moon (Elemental Enchanter Series) (Volume 1)

Falling in love isn't the only problem for Ava Hannigan. 

When seventeen-year-old Ava discovers that she can breathe underwater, she's disappointed. She wanted to be normal and dreads the day of her initiation into one of the most powerful covens of Elemental Enchanters. She has fallen in love with a human, which is forbidden, but she has such a strong connection with Peter, the only other person who knows what it's like to grow up motherless. 

Ava and her friends never expected to be caught up in the middle of a three-hundred-year-old war. Devon wants revenge against the humans for killing his master. Xavier, a ruthless witch, is building an army for Devon by spellbinding several students into becoming dark Enchanters. After Xavier realizes Ava and her friends are Elementals, Devon will stop at nothing to have their power. Xavier threatens Ava, attempting to coerce her to join them, but when she refuses, he kidnaps Peter. 

Ava must seek help from her coven to defeat Devon and accept her life as a witch in order to save Peter and protect the humans.