What to expect: World building, intelligent protagonist, weak to strong, hard-magic system.  Probus has lost his family to a huge war that swept the earth from alien invasions. He has been slaved and used for his intelligence and is sick of his life but he is given a new chance. He, who had lost his aim of life, has gained a new life, a new chance to become stronger and defeat the killer of his parents and establish peace on the earth.