It's such a shame this story got cancelled years ago. This is my favorite Masakazu Katsura title and outside of Sailor Moon, my favorite magical girl series. Great visuals, good action, some classic shounen humor, Shadow Lady is a pretty fun read that was cut far too short.
[STORY 7] Think of Saint Tail, except with a darker story and replace the bubbly cute Haneoka with a curvacious, bouncy Aimee. I've always thought this story and the protagonist as a telling of some kind of female Batman or something, what with lurking in the shadows (no pun intended) in a dark, Gotham City-style scenery (Gray City looks fantastic), and is still one of the more interesting anti-heroine/hero stories I've read in the manga universe. While this story was shortened and the plot is rushed, it's still pretty darn entertaining. I could easily have seen this saga being more than 100 chapters long and still kind of hope Masakazu has a chance to truly complete it.
[ART 10] These visuals kick assage. Gray City has a really cool gothic, middle age feel on the exterior while still retaining the countenance of a late 20th century metropolis. The penciling and the inking is fantastic, as much of the events take place in the night, the shadows never obscure the action and every panel is really crisp. Very clever use of multiple hues of gray and black do a great job of bringing Gray City to life.
The characters look great as always in the signature style Masakazu applies with all his works. I really love Shadow Lady's design and her alternate outfits. Next to Hime in Princess Resurrection, Shadow Lady is the sexiest female character in gothic clothing. I also got a kick out of Bright's wacky array of inventions he uses to fight crime. It's filled with lots of fan service, just a cherry on top of the sundae. It's pretty amazing how inoffensively perverted Shadow Lady is despite the lengths it goes to show skin, but that's been the author's signature since I can remember with Video Girl Ai and DNA2, and it didn't bother me.
[CHARACTER 7] It's almost a super hero parody at first, even to the extent that Shadow Lady becomes almost a celebrity. As with most magically altered personas, SL is pretty much Aimee's yang to her yin. I loved the police chief and manga's most useless cops try to foil SL only to get owned every time. It's funny that while I consider the titular character in the light of Batman, Bright Honda is actually the one with the goofy gadgets. I like this character, and he's one of the models of the awesome, yet epic fail male characters that I enjoy today. And Spark Girl is just plain hot, and she wasn't in it enough.
[ENJOYMENT 8] It's light-hearted fun of a girl with mysterious powers that gets pretty gripping near the end. Shadow Lady has a pretty high reread value in my collection. It's got a very entertaining lead character, an enriching setting, enjoyable support characters, and despite a rushed ending, was a little bit satisfying, although there's still some very important unanswered questions.
[OVERALL 8] This series has been a classic for me for quite some time and fans of the author will enjoy it. While it misses certain aspects of plot development and character depth, it makes up for it with an all around solid plot tied with good comedy and great artwork.

PROS: Excellent art, cool atmosphere, good characters, solid story
CONS: Too short