@miraianna i think the people calling him a simp are referring to the novel lmao. i'm not gonna give any spoilers, but damn our boy is mad in love.
yes, he likes her because she's pretty, an actual intellectual, and cunning. he doesn't want an innocent girl who's only good for being a trophy wife. he approached her after the hourglass shop incident because he was hunting for info about the count and aristocratic faction, so i don't think that's stalking, that's more like spying (altho from aria's perspective he's creepy cuz she can't see his motive like we can). he found that the things she predicted came true, and that led him to be attracted to her wit. i don't think he was ever deceived by that "pure, elegant, naive" front she puts up to mess with mielle. seems to me he always knew she was acting in some way or another.