They were swift, overtaking the lands with technology not yet made or seen until that moment. Robots hulked across the earth, machines roared, bellowing fire and energy as in their wake: destruction was left behind, as were desolate villages; their inhabitants once peaceful became prisoners of war, ferried in barges that took to the skies and remained out of reach in ships that blot out the sun.
They were endless. They were powerful. They were unstoppable.
Rise as the resistance did against their wrath, it was short lived against their technological prowess. Bows and arrows did little to dissuade the machines above and below ground with their limitless, and seemingly impossible to stop force. Swords, shields, and traditional gunpowder only did so much before defeat became all too clear.
For one, a would-be leader using a sword stepped forward. Her band of allies dove into the heart of the conflict, into enemy lines, using their machines against them, and harassing their army at every chance they got, delaying their advance, and halting it ever so briefly in their efforts. However, like every hero who rose up against them: they fell, harder than any one ever did before them.
Lives were lost, and a select few were chosen to live. Their options were far from numerous; to surrender and become a prisoner, die with dignity as heroes, or join him and become legionized.
The arguments made for their choices lacked a rebuttal. Their leader, broken down and handicapped, stepped forward, the first of the remaining four who would. She would join him. They would join him, if only to give mercy to the rest of their unravaged homeland, and to see most of the prisoners released.
But first... they would have to become willing subject to science, victim to the whims of experimentation.
Weeks within a compound established high in the mountains saw them modified, changed, and experimented on. Robotics, grafted to their once pure bodies, tainted their soul. Words and machines fiddled around in their minds, twisting chemistry, altering synapses, warping their perception. Two broke. Two did not.
As one who did not break, one who had a resoundingly stronger will to not be destroyed with that had been witnessed, felt, and experienced... a panda, Erita Aichi rose up with a new uniform, a new look, and a new perception upon her home; a powerful figure with eyes wrapped in darkness, shadowed, and with an eerie red glow traipsed across the countryside to the remaining settlements with an offer.
An offer for their compliance, given with an open hand, and a twisted, welcoming smile.
"Join the Empire, or suffer just as our homeland did."