I was very adamant that I was going to favourite Ava Wilson, who was one of Azazel’s special children back in Season 2, as she goes from an innocent and caring young woman, who desperately tried to warn Sam about her vision of him dying, to a slightly psychotic, power-crazy, demonic killer. In spite of all that, it appears that Ava was only featured in two episodes. So, really her amazing story arc was squashed and downgraded. I said that she developed from nice to naughty but in actual fact she was just nice in one episode that she appeared in and then completely not nice in the second. If her character journey was executed a little better, I probably would have chosen who story arc as my favourite.
I thought that Ava’s arc was very similar to Anna’s (who I talked a lot about in Day 4) as she also goes from a weak human who has to be protected to a very determined, powerful being and, when she gets her grace back and is betrayed by Castiel, she decides to try and kill Sam in order to stop Lucifer. Even when she turns darker, we as an audience still understand her actions and feel a little sympathetic towards her because we have seen her story unfold.
I also considered Mary Winchester’s story arc for a bit because, again, she goes from damsel in distress to badass hunter but I wouldn’t say that she strictly has a story arc because she dies in the first episode, and the only information we get of her prior to that is due to Sam and Dean travelling back in time. So, really, we are following her story arc but we’re doing it backwards.
In contrast to all of these characters who go from weak and vulnerable to sassy and strong, my favourite character arc would have to be Bela Talbot who, I think, goes the other way around. Bela starts out authoritative and cocky and then, during her last appearance before her death, we learn that she sold her soul in exchange for the death of her abusive parents. We have gotten to know her character throughout Season 3 but that last scene (in 3.15 “Time is On My Side”) before she is dragged to Hell is just so emotional and sorrowful. This badass character we have come to know and love has turned into a vulnerable little girl again, desperately asking Dean for help when there were times when she would point a gun at him in hatred.