HanaOmo: Great Machine

"The empire I once served has killed my sister. By axe and gun alike, I will purge its ruler for their betrayal of trust!" Left to die on an apocalyptic surface for vague reasons, a genetically engineered soldier of war swears to destroy the medieval kingdom she once served after she believes they abandoned her and her sister in this eternally dark winter hell. Armed with a spear and sword, allied with a giant machine of war naming itself the Great Machine, and blessed with fire magic from her mother-deity, the warrior sets out to bring vengeance to her sister's name. Except her sister is still alive. Unaware that her kin is about to bring destruction to the civilization of clones living underground, she rallies the many kingdoms inspired by Iranian, Indian, Japanese, and Celtic mythologies together to face a threat never faced before in this new installation of the world of HanaOmo! But her leader looks at the Machine with shock-ridden eyes. What do they know about this Machine? Did they know each other once? And why is the sun smiling at them both?