The Age of Mechanical Mercenaries

In a parallel future, the world is home to mechanical life. Here, people and mechanical beings cannot be distinguished by appearance alone, because mechanical beings can grow and develop too, even possessing body heat and blood, and thinking for themselves with brain-like structures, almost just like humans. The only difference, perhaps, is that once they reach adulthood, their appearances never age, until the mechanical organs inside them can no longer be replaced.

But this level of technology comes at a price. War is constant in this world, and humans and mechanical beings have never known true peace. At this time, human and mechanical scholars join forces to create new war machines, condemning these powerful beings to spend their entire lives fighting.

The mechanical mercenary Xiu Ye is one of them. But in the eyes of most humans and mechanical beings, he is a complete failure, simply because he has two bodies and two personalities, like someone with multiple personality disorder. According to his creator, Xiu Ye once had a mechanical sister named Xiu Nasi, who later died on the battlefield. Somehow, Xiu Ye brought Xiu Nasi into his own body, and from then on, they shared one existence. To find out how Xiu Ye had managed this, someone deliberately hired mechanical mercenaries skilled in stealing secrets to seek the answer. But they either came back empty-handed or were killed by Xiu Ye, whose personality was split. Later, Xiu Ye disappeared from the battlefield, and everyone eventually forgot the question...

Seven years later, a male mechanical mercenary named Ling Erxiu saw the long-haired, stunningly beautiful Xiu Nasi on the battlefield against an enemy nation. She single-handedly wiped out an entire regiment, but then collapsed after running out of energy...