The main thing with people thinking of crona as a male is the result of a lack of gender-neutral pronouns messing things up. When Medusa is talking about Crona she always says things like "That child is my flesh and blood" instead of son/daughter in order to keep it ambiguous, but in a few casual conversations I want to say Crona is actually referred to using "he". That said, Crona doesn't have a canonical gender