Mysterious Forest (Warriors of Nyx: Book One) by Yvette Poshoglian

The Realms of Nyx have been peaceful ... until now. Short-eared elf Dru is a warrior in training. Long-ear Bren is an apprentice mage. Their two tribes have been taught to distrust each other. But when their families and entire villages suddenly disappear, Dru and Bren only have one choice: to join forces and enter the Mysterious Forest in search of those they love. According to legend, the forest is full of terrifying and mysterious occurrences and creatures. Dru and Bren have zero reason to trust each other. To make matters worse, neither elf has ever dared to enter the forest alone. And if their villages have been taken by the soul suckers, as they suspect, then entering the forest is the worst thing they can do. Will they be able to find their loved ones, or will they disappear into the forest without a trace? Or worse, be taken by the soul suckers?