http://www.attackers.net/works/-/list/=/article=series/id=5040/

Attackers' "Slave Castle" series is often thought of as Slave Island's femdom lesbian cousin, and that sums it up nicely. The fate of the captured women is still unending sexual slavery, but overall it isn't portrayed as violently or depressing. The dommes of the castle are all women: MAYA, Riria, and one or two guests that change per episode. Most of the slave women are betrayed or sold by somebody they know, who may or may not get in on the action.

- Of particular note is the rape room filled with masked gimps that the slaves get sent to for disobedience. They'll spend days there (indicate by clocks or X Days Later captions). There's actually a "Best of" video that entails only the male-dom rape scenes of the series. It is hinted that all of the gimps are ex-boyfriends and husbands of the enslaved women

- Pretty much every single episode involves Gothic Lolita Riria fucking the slaves with a strap-on, and forcing them to eat her out.

- The slaves wear bondage and belts at all times, and little shiny tags get attached to them to indicate each time they've been fucked. By the time the episodes end, the slaves have quite the collection!

- Lots of fake enemas, collars, leashes, doggy bowls, and all that standard BDSM stuff.

- Chairs with dildos sticking up from the seat are common, as well.

There's not really much to cover for the series like there was for Slave Island, but I think a short overview like this would be appreciated here.

Slave Castle 1 - SSPD 066 - The third domme in this episode is ridiculously hot, and the other guest dommes are pretty sexy as well. At 52 minutes, the slave tries to escape, and gets nearly drown as punishment. The dommes kidnap and gag the slave's boyfriend, and Riria rides him in full view in a great scene.

Slave Castle 2 - SSPD 068 - A young woman is betrayed by her coworker. This episode introduces extensive time skips (2 days later after the first "inflation" scene, "4 days later" going into the first dog bowl scene). 53 minutes in is a nice ring gag scene, the two hot dommes forcing the slaves to eat them out. There's extensive male-on-female rape, and some interesting gags as well.

Slave Castle 3 - SSPD 072 - There's a new female domme here, and the two slaves are bound chest to chest. One of the slaves underperforms and gets a nice long whipping, and after that, a visit to the rape room where she is chained down and savaged by gimps for hours. Overall, a pretty interesting episode.

Slave Castle 4 - SSPD 073 - Extensive use of time in the rape room. The actress is reasonably good. As hours pass for the slave, Riria just looks so bored as she's reading a book. It ends with her licking up a puddle of cum that leaked from her cunt. Overall, one of the better episodes.

Slave Castle 5 - RBD 176 - A perfume creator overshadows a coworker, and gets sold in an act of revenge. Riria rides the boyfriend gleefully.

Slave Castle 6 - RBD 191 - The entry that killed the franchise! The woman is actually really pretty in this one, but her acting is awful. At one point, she gets sent to the rape room, and a "one week later" caption pops up. She barely even looks fazed!