A hacker for the People's Liberation Army. Her official rank is NCO 5th class, a.k.a. Sgt. Major.
- Anime Chinese Girl: Interestingly averts almost all the typical stereotypes. She also has a detailed backstory, coming from Shennongjia, Hubei province, and being the granddaughter of a veteran of the Chinese Civil War.
- A-Team Firing: She gets into a shootout with Revy at point blank range while attempting to hijack Rock's car and every shot misses. Except poor Rock who has to contend with all the hot shell casings flying at him.
- Bilingual Bonus: After Janet smugly reveals how she played her like a fiddle, she furiously yells an untranslated "Ta ma de!" at her ("FUCK YOU!").
- Best Served Cold: At the end of her arc, she eventually gets her revenge on Janet by covertly transferring a large, ill-begotten sum of money to her bank account and then tipping off the Scotland Yard. Feng notices that Janet is probably smart enough to evade arrest, but she will in any case still be forced to keep a low profile for sometime in a remote location of the world, and knowing that she seriously inconvenienced her like that is satisfying enough.
- *Click* Hello: Suddenly holds Rock up at gunpoint while his car is stopped near the Yellow Flag, as she knew the bar is a regular destination of his.
- Deadpan Snarker: When a guy at an Internet cafe tries to hit on her.Random guy: Now that's a rare sight. You don't see many girls in this town in a net cafe. Hey you. Where'd you come from?
Feng: From the entrance.
- Desperately Looking for a Purpose in Life: Her family placed no expectations on her. She never developed any goals in life either, so they ended up booting her to the PLA.
- Do Not Go Gentle: Invoked. Once she calms down and realizes just how badly screwed she is, she resolves to fight with every fiber of her being.
- Forehead of Doom: Sawyer refers to her as "the forehead glasses girl."
- Gratuitous Foreign Language: Gratuitous Chinese in this case. One memorable exchange has her chiding Revy in Cantonese for being so mean to her considering they're both ethnic Chinese people. Once Rock translates it, Revy just scoffs at her. She's also a fluent speaker of both Mandarin & Cantonese.
- Hackette: A star example of the PLA's cyberwarfare division. Her superior proudly tells her she will pave the way for China's coming online army.
- Hidden Depths: "The only things I'm strong against are fate and beer." She says this shortly after it's revealed she can outdrink Revy.
- In Vino Veritas: After Revy pulls her to the Yellow Flag to learn more about her, they get to drinking, and in an unintentional example of this trope, Feng has massive alcohol tolerance and is still completely sober even after Revy gets completely smashed. This leads to Revy telling her a lot about the "El Baile de la Muerte" arc disaster, giving Feng a much better handle on Rock's personality.
- Living Is More Than Surviving: When she and Rock has a heart-to-heart talk, she argues to him that he really ought give up his life as a freelancing privateer, and just return to a quiet civilian life, saying that he might believe his life in Roanapur to be much less restrictive than his old one in Japan, but in her view, he has in exchange for this added freedom allowed his life and health to be jeopardized on a regular basis, and she sees the ability to live one's life in peace and without the fear of death constantly hanging over oneself as more important than any vague notion of "freedom".
- Military Academy: A graduate of the PLA's Communication Academy in Xi'an city.
- Nom de Guerre: Feng Yifei is a pseudonym; her real name is Li Xinlin.
- No Social Skills: Discussed and averted. She's quite comfortable with the atmosphere of a brothel. Revy expresses surprise at this, having expected Feng to be a geek "who lived and breathed awkwardness". Feng simply comments that her profession required "more skills than simply using a computer", such as being amiable.
- Not So Different: Her situation is uncannily similar to how Rock ended up in Roanapur, which is the major reason why he chooses to help her. This whole trope gets played out for the entirety of Chapter 85, which is essentially one long chat between her and Rock about how similar they are.
- Old Shame: It turns out that she has an incredibly embarrassing photo of herself floating around, and the fact that Janet somehow got her hands on it absolutely shocks her.
- Reckless Gun Usage: This is Black Lagoon so not unexpected, but of all the people in this series, she's the only one who doesn't have a holster and simply stashes her TT-33 in the back of her pants. Not to mention her waving her gun at a crowd of people with her finger on the trigger and holding Rock up at gunpoint after she gets disavowed by the PLA... though in her defense, she was having a bit of a Freak Out! at the time.
- Reluctant Fanservice Girl: She's not really a fan of her new Stripperific clothes, and she reacts with irritation when her new look attracts the wrong kind of attention.
- She Cleans Up Nicely: While hiding out in a brothel, Revy gets the girls there to dress Feng up in something more "appropriate" for Roanapur, including a long wig and rather Stripperific wear. Unfortunately for Feng, this leads to some perverts trying to hit on her. Fortunately, Revy and Rock are there to show them the door.
- Smooch of Victory:
- Once Rock decides to help her by passing along some useful information about Roanapur to her, she asks him why he's doing so. He says it's for his own reasons. So she walks up to him and plants one on him, much to Revy's surprise (and displeasure).
- She later plants one on Rock once again, to celebrate that his plans have succeed in saving her life (as well as the fact that she also managed to screw over Janet in the process as a bonus), but she makes a point of telling Rock to keep it a secret from Revy this time.
- The Scapegoat: Was made into one by PLA officials in order to hide their involvement after Janet "framed" her for a hacking job. She manages to return the "favor" later, by landing Jane in hot water with the Scotland Yard.
- Unwitting Pawn: She was completely played by Janet and didn't even know it.
- You Have Failed Me: Even though it technically wasn't her fault, Feng completely botching the operation to spy on Janet means the PLA has no choice but to order a hit on her.
Feng's boss back in China. He oversees her operations.
- Bad Boss: Despite the trope below, he still ordered the assassination of Feng as per his orders from Major General Liu.
- Benevolent Boss: Made an unauthorized call to Feng after she was "burned" by the PLA to let her know she was on her own and that he would do everything he could to make sure her family was taken care of.
- The Handler: He was Feng's only point of contact with the PLA.
- Professional Butt-Kisser: He's mostly concerned with staying on General Liu's good side.
Ma's superior officer.
- Insane Admiral: A general in this case. He liquidates the entire first division after the Germans catch on to the PLA's cyber-espionage activities due to concern it will damage German-Chinese relations. Though it seems so far, the only person slated to be outright killed is Feng.
- Internal Affairs: Operating as this to Colonel Ma's division after the Germans got solid proof they had been compromised by PLA espionage.
- He Knows Too Much: His suspicions about Feng jump up after it's revealed she knew about the existence of Annenheim Distribution, a PLA shell corporation that was supposed to be above her paygrade.
- Unperson: After the operation to spy on Rainbach AG is compromised, he orders the complete dissolution of the entire operation, including all peoples associated with it.
- You Have Failed Me: He's pretty furious with Ma's division for getting detected by the Germans.
General Liu's assistant.
- Adorkable: She spends most of her time looking like a deer in the headlights or awkwardly hiding behind her paperwork.
- Beleaguered Assistant: The poor girl has her hands full trying to run errands for her boss.
- Expy: Yes, it's true that Psycho-Pass came out years after this arc started, but DAMN if she doesn't look identical to Akane. Given Gen Urobuchi's involvement with Black Lagoon, maybe this was intentional.
- Only Sane Employee: She sure looks like it, especially when her superiors are having shouting matches with each other. She just tries to stay out of the fight and recite whatever useful information she has.
A Chinese operative in Roanapur.