Yeah, a favorite imaginary scenario that really gets these guys off is one where they are forced into being feminized and turned into submissive, "slutty" sex slaves who "live for cock," love to be degraded and humiliated, and are nothing but empty-headed, dehumanized fuck toys and receptacles for cum.

As is often the case with such fantasies, it's not unusual for the fantasist to imagine himself being in both roles - first he is forced into feminization himself, then he later goes on to force feminize other males. (Similar to how many people, particularly guys, who suffered childhood sex abuse go on to commit it against other kids.) And as is also the case with fantasies, particularly male sexual ones, there often comes a time when the imaginary isn't enough of a thrill - so the fantasies are acted out IRL.

It's analogous to male sadism and masochism. Turns out, many males with one trait have both.

Gore Vidal published a mainstream popular novel, Myra Breckenridge, that was basically a male forced feminization fantasy, in 1968. In the movie version, the "after character" of the man who was forced into a "sex change" against his will was played by Raquel Welch. Coz in their fantasies, all these guys imagine themselves as magically remade into one of the sexiest, most gorgeous women in the world.