I want to be kidnapped and turned into a guy's (or group of guys') complete no-rights no-limits fuckdoll. In my fantasy, it's a two step process.
First is the body adjustment, because not many people want an ordinary guy as their always-available sex toy. Strictly speaking I don't need to be conscious for this, but if my captor is sadistic enough he could use the pain and shock of the transformations as another tool to break me in. But it's a fairly straightforwards process. Surgery, hormones, the works. The end result is that my body is perfectly engineered for sex and not good for much else - Massive whore tits, plump dick-sucking lips that default into an open, inviting O-shape on a face that can only be described as slutty, complete with permanent whorish makeup. An ass that's been greatly enhanced in terms of shape and ability to take cocks. What becomes of my dick and whether I'm given a pussy to compliment my new form is up to my captors, but if it were up to me I'd have both - My remolded dick would be on the small side, but still big enough to make an easy target for abuse and humiliation and it would serve as a reminder of what I used to be, for as long as my mind holds. Of course, I'd never be allowed to touch it, let alone actually use it. My pussy would be always wet and always inviting, but just tight enough to provide exquisite pleasure to whoever's fucking me and provide just a tinge of pain to me that would, in time, melt together with the pleasure. Optionally (And preferred, due to fetishes on my part), I'd be sealed into a latex suit that would be painted up to look like a stereotypical blow-up doll to make my new role clear at a glance and mark me as completely useless for anything else. But not until after my actual body has been fully transformed. That way, even if I'm taken out of the suit later I'm still quite clearly just a doll that only exists to be fucked.
The second part is the fun part, though (And the one I'm piss poor at writing about). The mental adjustments. Through a combination of 24/7 porn exposure, hypnosis and mantras constantly being run through my ears (even when I'm asleep, though I'm never allowed any significant amount of rest) and brainwashing techniques that would make the CIA proud, my willpower and sense of self are gradually eroded down to nothing. At this point, I don't even think, but if I did I wouldn't consider myself anything other than a sex doll that exists only for Master's cock and cum. My mind would be a completely blank slate, open to whatever further programming my Master wanted to give me. For example, if He decided He wanted to start whoring me out, he could implant triggerable personalities to fit the clients Or he could even condition me to do something as simple and stupid as raising my arm whenever I get fucked. The possibilities are endless, and all up to whatever Master wants from his fuckdoll. Or He could just be content with me being a literal doll, knowing that He was the one who molded and created it.
Sorry for no pictures - I don't have any saved. If I were to post something, imagine something from the bimbo threads on halfchan or similar.