Kaze no Stra

Kaze no Stra (邪風〈かぜ〉のストラ) is a manga written and illustrated by Iwata Nawoya

Plot
The beginning of the end of the world. Humans face not the fate of death, but being enslaved to cruel demons. After eons of peace in the human realm, a heinous race of demons has suddenly appeared. With the wizards extinct, the only hope against the demons seems destroyed, but from this despair ridden land a mysterious boy has appears. Could he be the messiah who's come to save humanity? A magical fantasy woven by the bond between two brothers who've been torn apart, be ready to carve the roar of victory in your soul!