Under the Heavens: Sword of Fate

[Multiple protagonists + alternate setting + interstellar fantasy + semi-sci-fi + coming-of-age; an expansive, original world] This is a story of humanity's struggle against the gods. Faced with gods of overwhelming power, humanity develops god-slaying weapons, and a new profession emerges: god-slaying warriors! This book includes some mythology and even religious elements. This universe is twice the size of ours, and the same goes for Earth. Humans and other creatures are not larger, however, and ordinary creatures in this universe are twice as physically strong as those in our world. If it's not for you, please don't complain. Just move along.