Krell & Cyan 
 Emily was a human with special needs who required assistance 24 hours per day. Emily was also the daughter of the scientist who created Cyborgs. She used to adore them and she wanted to stop their torturing. Her best friend and her personal assistant, Mavo, is a Cyborg and she even had a little childish crush on him. As a result, she helped them escape, send Mavo to save another Cyborg who was being tortured and scarred and she got lethally shot. 
 Many many many years after Cyborg's successful escape, Cyan is captured by them. She appears to be a human soldier and she is after a bunch of humanlike androids, called Marcus models. The fleshy androids are very dangerous for humans and anyone that lives and breaths around them. Unfortunately they have managed to escape Earth and death is following them anywhere they land. 
 Cyan used to be Emily. At least a more advance version of her, after her dad work on her almost dead body. 
 Krell is the Cyborg that Mavo saved during the escape. Scarred and lonely avoids everyone except Mavo who is his best friend. 
 It is time for a reunion, but Cyan cannot convince Krell that she is the one that saved them. She does not resemble at all Emily anymore. She is shorter, indestructible, deadly and a true soldier. 
 Krell is another Cyborg who hates humans. Cyan will make him see the light and subsequently Krell will be totally addicted to her. Ah, true love is all around... 
 Cyan/Emily is my favorite kick-ass heroine in the series so far. She totally steals the show and shows Cyborgs a few tricks.