Compared to several other inks I'm using at the moment, Midnight Emerald is fairly resistant to feathering. Yes, it feathers on cheap paper, but it's minimal. Honestly, it's fairly similar to Noodler's X-Feather, which I happen to still have inked from an earlier review.
And then, there's the shading. I'm a huge fan of inks that have shading properties. Can't really explain why, but I know that shading makes me smile. I like the variation in color and depth. It's adds more character to the pen strokes and adds (subtle) visual interest to the letters. In this ink, it's not extravagant, but it stands out enough to be a delight.
The color/hue is similar to Sailor Yama-dori. When you compare them side-by-side, the differences are fairly obvious, but the basic color is close. Basically, it's a dark green. I wouldn't go so far as to call it a black-green, but it's dark. Only on thin, fast strokes does it turn to a medium green.