>>25175970It'll kill something anon, if that counts for an answer.
>>25176004General rule is that it has to cover the whole face, but I don't mind if they're simple or slightly dehumanizing. Even a simple visor would do. So stuff like those plastic masks at party shops you're meant to paint on, gas masks, scuba masks tend to work out for me. Anything else, it depends on the design I guess. I don't really find something like Darth Vader's helmet worn by a girl all that appealing whereas something like Q from Street Fighter, I could stand to see a girl wear his mask or a variation that has more feminine features on it at least. It's not ALWAYS so cut and dry to the point I can generalize outside that rule, but it's plausible for a character's face to be shown to some degree for some headwear.
Animal masks, I'm usually not a fan of except for maybe Kunimitsu's fox mask but that's because it's stylistic rather than realistic I guess.
And I guess cartoon logic/possession/symbiotic/expressive/etc., masks like the Gold Block aren't possible outside 2D but yeah I'll lean on that sort of direction for stuff I'd like to see more of depending on its design.