Genre: fantasy/supernatural action romance
The art style is unique, full color, and somewhat more 'painterly' than usual
I think it was originally published in Korean or Chinese, started publishing within the past 2-3 years
vaguely 1930-ish fantasy setting

Protagonist: A cute and young white-haired maid

She decides to go searching for her "young master" (ML) in the big city.
She has prophetic dreams about monster attacks
She dreams about a monster attack on the train ride over and works with the 2ndML to stop it.
The ML has black hair and a sharp look, the 2nd ML is blonde.
The ML and 2ndML are working fairly high up in the military
She argues with the ML and convinces him to let her stay
the webcomic is PG-13 but is based on a mature light novel

at one point she is called upon by a princess who tries to have her killed
Both ML and 2ndML are embedded with monster stones.
much later, a 3rd ML appears who is a researcher with curly black hair

Pretty sure it is
Stigma Effect

many thanks
🙂