Under a sky, green and grey from the storm clouds and the light of the moons, the Modifier walked along a road that was cradled between three story blocks and glistening from moisture, reflecting the neon lights of this part of town. Few other people could be seen and not one appeared suited for what the Modifier had come for. 
“Hey, big guy!”
He stopped looking for the source of the voice. There was a slender, dark haired and fair skinned woman, leaning against a brick wall around the corner in a narrow back alley. She appeared young but very tired under a thick layer of make up, her tight rather sparse clothes unsuited for the cold, damp weather- and she shone like a diamond in his vision.
He had to search his artificial memory for prostitutes and pondered the right answer, since she was  the one , her body full of active an inactive nanobots, some from her customers, others from her pander, a dealer or some street doc, just to keep her body from getting eaten alive after getting infected by countless diseases from all over the quadrant and a bunch of possibly conflicting biotech. Larger implants in her cranium likely kept her docile and hard working, there was enough metal and synthetics in her body to actually work with.
He nodded slowly. “Do you have a room?” His deep voice was a little raspy and she smiled a fake smile. “Sure handsome. Follow me.”
The dimly lit room was dominated by a large bed with red sheets and a tall mirror over an old sideboard made from artificial wood, it was ripe with the smell of cheap perfume and air freshener.
The Modifier checked quickly for recording devices but the only bugs his finely tuned sensors found  were part of the rich diversity of vermin thriving on this dirty little world- just a possible source for protein he could later use. 
She closed the door and sat on her bed, patting the sheets next to her. Without a second of hesitation he sat down and as soon as she started to try and pull open the zipper of his jeans he put a hand on her neck. 
Fine tendrils made from the living metal that formed his skeleton pierced her skin- for a moment she looked startled and gasped as the robotic mycelia spread, linking with her implants and connecting them to formerly unaffected regions of her brain. Then she sat up, stiffening , her eyes wide in shock as he took control over her body. Her gaze defocused as the Modifier gently urged her  to kneel on her bed, the reprogramming was already getting hold of her damaged personality when he initiated the first Modifier-nanobot injection. 
The bigger ones of the advanced microscopic machines attached to the walls of her blood vessels and began to spit out countless lesser nanites that infiltrated the living cells of her body, smaller units spread through her system to assimilate all the other nanotechnology.. After her whole body was saturated  with his machines the Modifier could finally start with the real modifying. 
He pondered is a few more moment before finally choosing the kind of drone to start with, a infiltrator was always a good start on a low tech world like this- that and it would give the girl actually more control over her own life then she had before!
The Modifier closed his eyes, feeling her body through his machines inside her. He had her rise her petite rump a little and look toward the door, then started to slowly elongate her small frame. Popping noises from her spine could be heard as it was pulled apart, the widening intersections quickly filling with elastic but very tough cartilage, a groan escaped her when he also started to make the bones in her hands grow and her fingers shorten and thicken, changing them into strangely paw like digits. 
He took care of her legs next, shortening her sheens and elongating the feed instead so her thickening toes burst out of the tips of her boots and worked upward again when he was satisfied with her lower limps. Her ears shrunk back into her head and every single hair was reabsorbed into her skin as her skull elongated, her jaws where pushing out and her nose was flattening, giving her head a more ovid and reptilian appearance. 
With a sickening crack her ripcage widened, her heart and lungs grew as her humble breasts flattened against her expanding chest.  An elongating tongue with  a strange metallic sheen lolled out of her maw when a yawn that made mouth widen, stretched her lips into thin, bloodless lines.  New, large and very sharp canines, made from shining chrome that was taken from her now transformed or replaced brain implants pushed out of her gums and finally tiny scales, able to change colour in a split second,  replaced her human skin. With some more internal modifications that replaced a no longer needed reproductive organ with a secondary heart and converted the last little bit of her body fat into dense muscles the changes came to an end. 
The Modifier pulled his tendrils out of her and opened his eyes to check out his work. The former prostitute made a quite remarkable infiltrator drone. Her body resembles that of a borzoi or another sighthound now with her tank top stretching over  her enormous chest, a small, vestigial tail that created a bump on the back of her miniskirt, her head and skin on the other hand were very reptilian while only her pointy, segmented tongue and large canines showed the typical metal coloration of drones in a later state. 
He smiled and padded her back and she seemed to wake up from a deep trance, she shock her head as if to clear it and started to wiggle out of the clothes she didn’t need any longer. Her body was easily able to consume and convert most inorganic material now with nanobots in her digestive taking those apart and using them to reinforce skin and bones and since an infiltrator was a very basic model of drone she could also be developed into all of the higher forms if he needed a warrior, an assimilator or even a assembler or transport… but for now, she was just perfect. He chuckled and left the room as she started to gobble down the things she found in her purse, chewing on her cellphone.