WARNING: The following contains spoilers for Carmen Sandiego Season 4, now streaming on Netflix.
The fourth and final season of Netflix's Carmen Sandiego has V.I.L.E. (Villains International League of Evil) pulling out all stops to take down the Crimson Ghost once and for all. Carmen cost them too many heists in the past, but they were also keen on taking out the traitor and person who was now mentoring her: Shadowsan. This personal vendetta brings the sinister society's most lethal assassin, Lady Dokuso into play. Unfortunately, her skill and expertise is wasted yet again.
In Season 2's "The Daisho Caper," Dokuso proved her mettle, partnering with Paper Star in Japan to kill Shadowsan after V.I.L.E. faked a sword heist. At the Yakuza nightclub she ran, Dokuso lured him in, almost poisoning him with chopsticks, as toxins are her specialty. Thankfully, Carmen saved her father-figure, but from the fight Dokuso and Shadowsan had, it was clear they were meant to be mortal enemies as she was pretty superb in battle.
Still, their brawl was so short and should have been fleshed out, especially as it's not usual to see Shadowsan tested like that. The fact Dokuso wasn't brought up to the main faculty that season, and that she didn't get a prominent role or revenge in the third season either, was disappointing. However, the Season 4 premiere, "The Beijing Bullion Caper," does seem like it rectifies that by having Dokuso go undercover with Neal the Eel. Their job is to kidnap Huang Li, manager of the gold bouillons in China's largest bank, during an ancient dance ritual and get him to turn over the loot.
Dokuso once more shows her worth with chemicals, knocking the manager out with makeup, but Team Red steals him back. This leads to Dokuso once more scrapping with Shadowsan, and it's a brilliant display of kung-fu. She again seems to be his equal, if not better, and wants revenge for when Ivy and Zack foiled her attempt at knocking out Huang Li with poisoned tea earlier on.
She vents her frustration and cuts Shadowsan in their fight, causing him to fall off a building, poisoned and in pain. It reiterates how effective Dokuso can be, and had she the right support to take on Carmen's squad when they come rushing in, she'd get the job done.
Yet, while Dokuso escapes, the show doesn't bring her back for the rest of the season. It's a really underwhelming swan song as it feels like her rivalry with Shadowsan never lives up to its potential and doesn't get the closure it deserves. A rematch to settle a winner once and for all would've been appreciated by viewers, but sadly, when Julia and A.C.M.E.'s agents have a debriefing after V.I.L.E.'s faculty is arrested, Dokuso is present with the others like the Troll, still on the loose.
Starring Gina Rodriguez and Finn Wolfhard, all four seasons of Carmen Sandiego are available to stream on Netflix.