Going through the comments it's obvious what the conclusion will be, but honestly I'd say it depends on context and if there's a proper term that can accurately replace the honorific. Like with the two examples provided, Hero already has a connotation to it that implies how important that title is (unless the context of the story tells us otherwise, as a recent anime has shown) so the "dono" part isn't necessary. Priestess is a bit different since there can be various types of them that can share that title, so we need to know how important this particular priestess is compared to the rest which is where "sama" can be useful. However there are words you can use to show specificity in her rank like "Madam Priestess" or "High Priestess".
Personally I'd say to avoid it unless necessary. People in the comments have stated "well in Japan", but that's not where we are right now so that argument is irrelevant imo. At the end of the day though it's up to y'all. If it's easier to just keep in the honorifics, go for it. It doesn't take away anything with it's inclusion.