I would argue that there was no real character Development for Dedra. At the end of the day she was what she was...its just that her house of cards ultimately came crashing around her at the end.Personally, I liked it. I thought that it and the inanity of it should have affected Dedra more. It seemed to at the time, but then after the time jump, there seemed to be no development. That was the only thing that it missed in the payoff. And Syril's character development also helped to develop Dedra which I thought wasn't wasted time.
I mean she was still the same arrogant relentless "I have to do it myself" individual in the second season she was in the first. Syril's relationship with her showed she at least had the potential to care for someone...though it also showed she had no issue manipulating him as well. And I don't see how his death really changed her actions. She was always obsessed with axis and getting the credit for it, heck they even commented after the botched work that had been warned about overstepping on other people's assignments. Syril's death didn't change her character in anyway I could really detect.