Danny was fueled with years of humiliation and feeling completely pathetic. He had let his tall, handsome friend go through high school without a care in the world. His gorgeous brothers and sisters for no fucking reason at all got the great genes from their parents while everyone made fun of Danny for being a gross, flabby little weakling. It was time to set things right.
Danny set the Chronivac to steal 4 more inches from Jeff's height, so he could truly enjoy being a pathetic short dude. He then set it to remove Jeff's arms and legs, only leaving a few inches of all four limbs. Jeff could be a helpless little fat dude completely dependent on his friend. He increased Jeff's weight to 250 pounds—not counting the nonexistent limbs of course, so Jeff would be a proper tub of flab. "Fat marshmallow? Is that what he called me? Who's the fucking marshmallow now?" For good measure, he made sure Jeff had no body hair whatsoever. The sleeping Jeff now had a pathetically fat face, short stumps where his arms and legs should've been, and a huge belly and butt devoid of any definition. Danny considered robbing him of his cock, but that would really be cruel. Every person deserves a dick, he thought. Otherwise what's the point of living?
He scrolled through the Chronivac's advanced options. "Jesus Christ," thought Danny. This device was designed by an absolute psychopath, or a committee of psychopaths trying to outdo each other. He had to ignore most of the creepy shit he saw there. He wanted to bang his friend and embarrass him, not subject him to cosmic sexual horrors nobody could never recover from. He tried to stick to things that were fun but made at least a little sense.
The one thing that was important to him were the mental changes. He wanted Jeff to feel the humiliation of his new body, but he didn't want Jeff to have no pleasure at all from what was going to happen. It's fun to fuck somebody nervous but willing. He settled on two changes for Jeff: First, Jeff would now find tall, muscular men with large cocks extremely attractive. He would forget about Sam and the other decent-looking girls from their class. Second, Jeff would have a more powerful orgasm the more he was humiliated about his body.
"This feels like a good trade-off," thought Danny. Obviously Jeff would be horrified when he first got a look and a feel of his useless, flailing stump arms and legs, his massively fatter body, and the absolute power that Danny had over him. On the other hand, Jeff would absolutely crave Danny's monster body and would beg to be humiliated as much as possible so that he could achieve the mind-numbing satisfaction every teenage boy craves. Danny, after a moment of deliberation, pressed "Start".
Now, Danny's incredible monster body and his 4- or 5-foot rock-solid cock would be matched by the helpless, horny, begging marshmallow that his friend would be stuck as. Jeff would always be begging for the monster Danny to fuck him again, even as he would forever be unable to walk, jerk off, or even wipe his own ass again. Jeff's whole purpose—the fat marshmallow, the human sextoy—would be for Danny to service him again and again. While his mind remained, and he was furious at his fate, the pure sex-fueled desire for Danny's body and being constantly humiliated would always overwhelm the sensible part of Jeff's brain, just as the amputation would forever prevent him from walking or climbing or typing, no matter how desperately he willed it.
As the transformation began, Danny watched his new helpless fucktoy come to life.