"Computer, permanently install the Succubus Upgrade." Samus said it fast, giving herself no time to regret or change her mind. The positives outweighed the negatives heavily, it would have been a foolish choice to give up such great abilities.
Samus looked at herself, she didn't feel much different. She checked the upgrade slot once again only to see it was completely gone, without a trace. It must have merged itself with her body, altering it's structure from within. Seconds passed and samus still felt nothing until she suddenly fell over in pain, her head ringing louder than 1000 screams. She couldn't think or concentrate, all she felt was the inner workings of her mind and soul being molded to fit a demon. The computer was right, her body, mind and soul were rapidly shifting and contorting as they were modified by the Succubus upgrade.
"Please, make it stop!" Samus cried, only to be met with even more pain. She was splayed on the floor, writhing in agony. In that moment, her breasts exploded in growth, each becoming a bit bigger than her head. They jiggled all the while, as Samus uncontrollably moved around in pain. Her ass quickly followed, becoming similar, if not better, than a strippers fat, jiggly, bubble butt. Her hips cracked and widened as her wings shot further out of her spine, sending more sharp pain throughout her body. They were now big bat-like wings, easily capable of flight. Samus couldn't catch a break, her waist sharply narrowed, as if being sucked in by an invisible corset, giving her an extreme hourglass figure, she was the perfect succubus, her sexual body purely formed for debauchery. Her shoes were altered as her feet grew into permanent high heels made of her bone. Last but not least, her demonic horns got slightly bigger.
Samus suddenly stopped shaking, no longer feeling any pain. The modifications were all done. Samus took many deep breaths before finally being able to stand up. She walked across the room, a tapping sound following as her new bodies heels hit the ground. Her wider hips sensually swaying from side to side, forcing her breasts to bounce on her chest. She reached the computers darkened screen and got a good look at herself.
She was perfect. The upgrade hadn't altered her perception, she was genuinely in love with her new look. She moved her wings and began to fly, aiming her blaster and throwing a kick or two. "A lady could get used to this..." she said in a particularly sultry manner, not only had the upgrade altered the way she carried herself, moved and thought, but she couldn't resist speaking seductively. She'd become a pure blooded succubus.