Guardians of Gayrile by Alice Bjornstedt

Who am I, really? That is the question Rygal has a asked his entire life, ever since his father was a killed defending the tiny island kingdom of Gayrile from her enemies–a sorcerer with great powers. Now the same sorcerer has returned...and rumors say he has sent an army of undead warriors to besiege the Mainland capital of Caer Sia, the last hope Gayrile holds for freedom. In the midst of war and chaos, surrounded by newfound companions, Rygal seeks to unravel the mysteries surrounding the legendary Guardians of Gayrile...and learn if they can be rallied again.