Yeah I was going to say Loki's "default form" was a he since he could shapeshift at will, sex included, but I thought that would complicate things.
Was also going to note Loki-Shinji also did the "changes every time they check" thing but that could've also been foreshadowing that he was really...
I also haven't seen the Japanese chapters so I can't say for sure, but I wouldn't be surprised if neither masculine nor feminine references were ever used for Shin, since it's easier to do that in Japanese. With such ambiguous characters scanslators tend to pick a "he" or "she" and only change...
I for one wouldn't mind if the Will of Mana were taken down in a single page like it was nothing then everyone got back to focusing on what really matters.