Well said Jacob.

Any time you are putting an event like that into a story, particularly a collaborative story, you should consider if this is something you're going to come back to or something you are just doing to try to drum up interest.  Drumming up interest is all well and good, but it can be pretty clear when you are having Dirk Daring doing something horrible just for shock.  Cruelty, violence, rape or implied rape, anything like that really can add to a story but it can also take away quite a bit from a story.  I may not want to participate in a collaborative story if halfway through it I find out that the character I'm partnering up with has a backstory with elements like that in it.  It is also easy to attempt to go for an anti-hero or dark/gritty/edgy etc etc character and end up just making someone unlikable.

I tried to do a Deadlands RP years ago now and had some issues with the taboo.  It's a setting that proposes the Civil War Never Ended and changes some pretty major details of history.  In this setting the South ended slavery before the North, though largely just to get military assistance from the French.  Also the dead walk the earth and there are poker playing demons.

It could be a fun setting, a supernatural western, but it touches on a lot of contentious things.  The Civil War, Slavery, Colonialism and Cowboys & Indians among others.  There is a lot of interesting history there, but also real people and some real pretty ugly incidents.  I've contacted a few people here to see if they would be cool with me running stuff by them if I ever actually do the RP, mostly people with Native American ancestors or people with more knowledge of colonialism.  Then there's another way to do something like this...

Actually I'm not going to link to it as the author is still around, signed in a month ago, but there was a Western RP someone else started up where they just replaced the different races of the real world with Warhammer races, which presented obvious problems and so never really got started.  I think a few of you were around for it, it pretty quickly fell apart with the question of who would the orks stand in for.  Yeah.