Definitely Monster, as you said

Maybe Logh? I don't usually think of sci-fi as prestige TV. Similarly, Baccano! kinda hits some of your points but is modern urban fantasy.

I haven't seen it in years and don't really remember the plot, but maybe Michiko and Hatchin would fit the bill. Also Moribito could fit, which is set in feudal times but very light fantasy element if any.

How about Leader, the Chiname about Marx & Engels? Perhaps production value too low