>>49655413
Starting with DiPP and EoSD, 2hu dresses became more elegant, frilly, and generally overdesigned.
The stories also became more grandiose and dramatic, sometimes even veering into horror. That's especially clear in the Hifuu albums, which often leans into cosmic horror.
The music also gradually became more traditionally western, mostly using the piano and trumpet, although it never fully abandoned the digital style. An early frog leap in the music is Remilia's theme, with its reference to Beethoven. Interestingly, the DiPP music doesn't fit into that, being way more experimental.
The nameless girl drawings gradually became more detailed and the clothing became more frilly. The cleaning maid is the first one you could really call "western" in theme, so it's the first one I'd call "gothic".
It's interesting how you can connect these various influences. The "Kwaidan" are ghost stories, Lovecraft was very much influenced by Hearn's writings, and Agatha Christie is often accused of orientalism, although in her case it is about the Middle East, not East Asia. I think the combination of all of these distinct but connected elements, combined with the child-like air that has been present since the second game creates the very distinctive yet cohesive aesthetic that everyone recognizes but many have a hard time identifying.