I was not here for the relationship between Aizen or Rangiku, and most definitely not Jan, but it is clear as day that it had a great impact. She was pregnant at the time of the...my kidnapping. As well as locked away, and... it may be because she lost Haineko, which is a notable part of her soul. With the balance thrown off, it allowed the lure of darkness to 'corrupt' her.

I don't think right now she is too concerned about the sword. As for Jan, he seems content on believing it is a clone of her... His actions aren't comforting either.