>>10907760While I don't have any good pics, Marvel Legends MCU Ghost had a really nice, really deep elbow bend on a single hinge, without having a large bulbous joint in it. And as others pointed out, many JP lines have also done single hinge elbows with tons of range, in particular the now defunct Busou Shinki line had excellent elbow range on a single hinge.
Now admittedly both the ML and Shinki had slender arms, but imo it's those arms that benefit from the single hinge look the most. Large bulky arms can better hide a double joint while making it look more natural. But a slender arm with a double joint just never looks good to me.
It really comes down to the cut of the joint, but a lot of work is also done at the wrist area as seen with Sonia. Her elbow really only bends to about slightly better then 90 degrees, but that vertical wrist joint has so much range, the limited elbow is hardly even noticeable.
