Demon Eyes

Below the world of humans lies the realm of demons. They watch over humanity and grant the humans they like most a piece of their power. Humans blessed by a demon manifest a Demon Eye, allowing them control over one of the many natural energies in the world. Most humans only ever receive one such blessing, maybe two, but one boy by the name of Noreyu has a Demon Eye with control over all known kinds of energy. He and his friends live a peaceful life, until one day, they suddenly become targets of a mysterious group of assassins. Someone powerful wants them all dead. How long can this group of four survive with targets on their back?