I just recently discovered Sedna, so I decided to look it up in my chart where it falls at 11Taurus21 in the 8th house. This fits perfectly with what I know of Sedna and how the theme of being a victim shows up in my life. I've noticed that in relationships, in my past I've had a hard time setting boundaries with sex. So with an emotionally distant or inconsiderate partner, I wouldn't know when to say no and I'd end up feeling victimized. Then I looked some more and found that at the time (I don't have the exact date, but Sedna moves so slow it doesn't matter anyway) I was sexually assaulted by a "masseuse" (I know he wasn't licensed) transiting Sedna was exactly opposite my natal Pluto, which among other things rules sex. I also read that Sedna oppositions especially tend to bring in people, either victims or victimizers for whatever event occurs.
This planet really resonates with me. It seems to fill a gap that my natal chart didn't explain. I definitely feel that having had these experiences, my challenge has been to rise above the victim-sympathy payoff cycle to assist others who've been through similar experiences. In a strange way, this has been a very valuable experience. I have so much more compassion for a wider range of people.
I recently had the opportunity to be witness to some incredible healing that occurred when several people who had at some point been the perpetrator of a sexual assault, shared how that affected them. I'm not condoning the act, but the pain behind it, that drove it, was a revelation to me. To know that there is pain on both sides inspired so much compassion. In that same instance I was profoundly inspired to see men and women who had been victims of similar acts, rise up and, as one, forgive those who had been the perpetrators. I feel that this entire experience is the epitome of what 8th house Sedna represents to me. The transitioning from the lower octave, victimization, to the higher octaves, forgiveness, compassion, and empathy for those in similar straits.
I hope this has been of some use to you reading this post. I didn't really intend to pour my heart out this way, but oh well :)
I really love hearing what your experiences have been with Sedna. Its very eye-opening.