Valmonica Scelta:
Full art:

“An uneasy look, as if she had been entrusted with the fate of the world”

Note: The title of this reference art is “The girl chosen by the Valmonica (temp.)”, with a clarification that this ended up being used as the reference art for Valmonica Scelta.

Source.

Demone:
Full art:

Hair:

“Large hair buns”

Appearance:

“Is it because of my appearance that no one listens to what I say? *Frustrated sounds*”

Angelo:
Full art:

Hair and laughter:

“Small hair buns”
“Ehehe…”

Strawberry:

“Strawberry-like”

Wings:

“If you look closely…aren’t its wings upside-down?”
“Scary…”

Siesta:

“Time for a siesta, you know?”

Whispering:

For these two, a direct translation is more complicated. Demone and Angelo are implied to be whispering to someone, most likely in a gambling situation. Demone is saying “matching 2 out of 3 dice is not actually close!”, suggesting that the person shouldn’t consider this a sign that their luck will be better in a future roll, whereas Angelo is saying “just double down and you’ll turn it around on them, of course” while smiling, giving the exact opposite advice. This is playing on the general idea across this reference art that Demone and Angelo’s personalities are the opposite of how they look.

Source.