Nate here. This review goes over the following anime, Darker than BLACK: Kuro no Keiyakusha/The Black Contractor, Kuro no Keiyakusha Gaiden/ The Black Contractor Gaiden, and Ryuusei no Gemini/Gemini of the Meteor.
First of all the Darker than Black series has been going on for quite awhile, and has finally finished with the Gaiden OVAs. Though saddening tons of fans hoping there would be more, but yes it was a very fulfilling anime series.
The anime, overall, talks about contractors, people who have special powers at the cost of losing certain emotions, the Syndicate, an organization based with a certain group of contractors giving out missions etc., and Hei, the Chinese main character of the anime, who's power is to use electricity. Supposedly not having any emotion, but shows hints every so often.
WHY SO SERIOUS???
The 2nd series, Ryuusei no Gemini's main lead is a girl named Suou Pavlichenko, a Russian girl who got hit by a mystery light during the OVA of Kuro no Keyakusha Gaiden. When she got hit by that light, she became a contractor. her power is the ability to bring forth a massive sniper rifle and 5 bullets in her pocket.
I love sniper rifles, thus she is awesome. =D
The Gaiden series is simply what happened in between series 1 and 2, so not much to say there.
Honestly I'd like to see more Darker than Black, continuing from Ryuusei no Gemini somehow. Suou kicks ass. Though the emotion loss is kinda saddening for the guys she meets up with. I also wanted Hei to meet up with Kirihara, but he never did, sad for her too. lol, so many things that never managed to happen. There's so many things I could talk about, but I could only sum it up with this; If you plan to watch Ryuusei no Gemini before Kuro no Keyakusha, bad idea. Watch it in order. Though the Gaiden (and the unspoken special,) is an exception.
Great anime, 4.9 out of 5