Maybe it's just me, but the last few sets have seemed more flavorful than previous sets, and Nocturne seems like the most flavorful of all. The secret history also mentions a few cards that seemed to start with a card name and found mechanics that matched (Necromancer, Vampire, Werewolf, sorta Changeling, maybe more).
So, I was wondering has flavor become more important for you in design? If so, was that a conscious decision? If not, have more recent sets just become more flavorful because you've gotten better at naming cards?
For the main set, no work went into the flavor. I at least renamed Circus to Festival and switched Bureaucrat and Militia (over objections - wouldn't playtesters be confused now? As if that matters). The cards are just what they had been, back when there was no reason to think I'd try to get the game published.
I put in a little work on flavor for Intrigue. Then from Seaside on, I more aggressively renamed things to fit the set theme. Still there were just a few cards here and there that actually started with a name or art; a great fit like Treasure Map was still, I had a mechanic, what should I call this.
For Adventures I tried to have a few theme-based cards, to uh push theme. The Peasant / Page lines started with names, and Giant and maybe something else. Empires was back to just giving cards good names; I don't think anything started with flavor there. I made a list of Roman things and you know, I guess this Landmark will be Fountain because it cares about Coppers and you like throw them in a Fountain. For Nocturne I specifically tried to have some flavor-based cards, in part because it fit with the mechanics - the mechanics were going after players who might also appreciate some nice flavor. And the extra cards help - you can guess that "Gain a Gold, if you have 7 cards in play gain a Wish else receive a Hex" is called Leprechaun, but I threw in the names "Wish" and "Hex" there, they help.
In general the two things in the way of flavor are 1) caring more about gameplay, and 2) caring more about simplicity. There's no way to have compelling flavor for Smithy; you don't look at "+3 Cards" and think "oh I bet I know what that's called" like you do with Leprechaun. You can add text to reinforce flavor, but that's adding text, and it's better not to add text. And then uh. Like let's compare two cases, Warrior and Vampire. Warrior can kill other Warriors. Flavorwise that makes sense. Flavor was actually one of the arguments for not preventing that. And it's like a stand-out mistake in Adventures, the fact that Warriors can kill Warriors. Meanwhile in the flavor-heavy Nocturne, Vampire cannot gain Vampires. That makes no sense, it's anti-flavor. I sided with gameplay! It's just always the move.