daizbella Renaissance Costume Women Ren Faire Dress Outer Garment Elf Costume for Women(Underskirt Not Included)

The garment is a chemise, it's literally underwear. A fantasy frock like this would go well over it. https://www.amazon.com/daizbella-Renaissance-Costume-Underskirt-Included/dp/B0FMJRQTMM Though finding one in a more gothic shade might be the hard part. Or lean into it being underwear, and throw on a lace robe/duster/kimono https://www.disturbia.co.uk/en-au/products/waterlily-burnout-fringe-trim-longline-kimono https://www.disturbia.co.uk/en-au/products/kobra-velvet-snake-embroidered-longline-kimono https://dangerfield.com.au/products/lush-burnout-duster