In its 10th season, Supernatural's new formula seems to consist of: 1) way lower stakes, as compared to the overarching plots of previous seasons, and 2) soap-operatic subplots involving Castiel and Crowley. To that end, the show has introduced the two most annoying female characters on television.
I know that's a bold statement, but last night's episode really backs it up. The "A" plot, to the extent that Supernatural even has "A" plots any more, is about Dean trying to get rid of the Mark of Cain on his arm — to which end, Castiel "borrows" Metatron from Heaven. Metatron volunteers the info that they need the First Blade to remove the Mark, but then won't share any more info without getting something in return. (And they work in a nice Revenge of the Nerds shout-out with Metatron (aka Booger) cackling about dweeby guys like him outsmarting the dumb jocks.) Dean ends up whaling on Metatron, but still manages not to kill the two random asswipes that attack him at the end of the episode. (More on them in a moment.)
The "Mark of Cain" storyline basically just creeps forward, and the main takeaway is that Dean is screwed unless he somehow removes it — he's doomed to turn into a psycho killer, like Cain. (Although Sam points out that Cain got it under control just fine — conveniently forgetting that Cain was a full demon.)
But a lot of the episode is given over to subplots about the aforementioned annoying female characters, in a show that actually has a pretty good track record of female villains and supporting characters in spite of its largely male-dominated cast. We have:
1) Claire, the daughter of Castiel's vessel Jimmy. She's pissed because her dad got possessed by an angel and basically disappeared, and now Jimmy is dead because Castiel got exploded once or twice too often. Nobody ever quite explains to Claire that Jimmy's sacrifice saved the entire world back when Lucifer was trying to create the apocalypse. Or that her ruined childhood is a picnic compared to Dean and Sam's ruined childhoods, or 10000 other people's on this show.
Instead, they just let her whine endlessly about her dead dad, and give Castiel attitude about his attempts to fix the damage he caused. She somehow manages to cling to the idea that Randy the creepazoid who pimped her out in the previous episode was her real family, and goes about finding a young couple who can replace Randy in the "creepazoid" portion of her life. It's actually sort of hilarious that the CW, which specializes in sad teenaged characters, features such a ludicrously unsympathetic teenager, who feels like she belongs on CBS. Or NBC, maybe.
2) Rowena, Crowley's mom. I sort of liked her when she was going around destroying demon brothels. That was fun. But the ageless witch who was a neglectful mother when Crowley was alive has quickly started to become an excuse for major campness, and not in a good way. She parades around Hell being transparently evil and flaunting her completely obvious agenda to overthrow her son, and somehow Crowley doesn't just toss her into a fire pit or something. It's partly because her comic dialogue is so broadly written you can't quite believe that anybody (including Guthrie the minion, this time around) would be taken in by her. I love a campy witch, but she's both one-note and grating. ("What the Hell is going on in Hell?" Ha ha ha ugh.) And she erodes the last shred of Crowley's credibility — why does anybody obey Crowley, exactly? Why is he King of Hell? He's already been a blood addict and hopelessly dependent on Dean Winchester's bropanionship, while Dean treated him like crap in front of his underlings. Why does anybody fear, or follow, this guy?
Really, the root problem here is not with Claire and Rowena. At all. Rather, it's with Cas and Crowley — two characters who were introduced years ago, had an interesting arc, and then stuck around because they were "fan favorites." It feels as though nobody quite knows what to do with either of these guys, but they're too popular to just put on a bus. The best thing would probably be to have a year or two without seeing much of either of them, and then bring Cas and Crowley back in a big way for the show's final season, which I'm guessing will be season 17 or 18.
The other problem is that the show's serialized elements are heavily focused on these characters' personal struggles, and we're now halfway through the season without the slightest hint of a Big Bad or any kind of over-arching threat. The last time I was really engaged with a macro-storyline was when Abaddon was creating an army of specially engineered demons, and that was a year ago.