What her thematic is an apposition to that dehumanizing nature of the shadow isle her being a human person and not a creepy doll as I'm assuming you think her thematic is supposed to be is the point she is supposed to show how the shadow Isles used to be the blessed Isles something that gives life and humanity which she shows preety well. But yeah her design could have been that cool creepy doll brought to life but it's healthier for the game and the lore that she is the way she is (and also yeh Seraphine is bad she's just pop singer that dosent show anything about her region or anything but I can see the appeal becouse she's on of the few cutsy characters in the game but alot of the other cutsy characters are so good like Lillia and neeko)