WARNING: The following contains spoilers for One Piece, Chapter #977 onwards by Eiichiro Oda, Stephen Paul and Vanessa Satone, available in English now from Viz Media.
One Piece's Wano Country Arc has introduced a slew of new characters, each with their own abilities, motivations and alliances. One of the more antagonistic additions to the story is Black Maria from the Tobiroppo, the six of the strongest members of the Beast Pirates, second only to the All-Stars.
Like the other members of the Tobiroppo, Black Maria's name comes from a card game of the same name from Britain. Her name may also be based on black widow spiders, whose females are known for eating their male mates. With her courtesan-based design, Black Maria owns a brothel on Onigashima. She's a beautiful, flirtatious character who even has a soft spot for children. However, she can be just as cut-throat as her peers, backstabbing and torturing anyone who gets in her way.
She captures "rebellious" men and tortures them to the point that they become obedient and loyal to her alone. We see this firsthand when she captures Sanji and begins beating him into submission. Despite her ruthless nature, she doesn't actually like getting her hands dirty, so she has her underlings do all of the work for her. Instead, she'll watch from a safe distance or wait with Kaido, preferring to let others do the dirty work. Despite this, she's shown to be a tactical strategist, knowing that she'd be able to capture Sanji easily if he were to try rescuing a woman.
Being one of the Tobiroppo, Black Maria is also a Devil Fruit user. More specifically, she uses the Kumo Kumo no Mi, Model: Rosamygale Grauvogeli, an Ancient Zoan type Devil Fruit. When activated, she takes on the appearance of a spider from the waist down. In this form, the two front spider legs have a personalized Jolly Roger tattooed on them. She has several spider-like abilities, like being able to walk on walls and create webs.
Black Maria was first introduced on Onigashima during the Fire Festival, where Kaido had her and the other Tobiroppo members brought to his castle for a meeting. Kaido tells them that he wants them to find his son Yamato and that whoever brought him to Kaido would get the chance to fight one of the All-Stars for their position. While the other five members went out to look for Yamato, Maria instead opted to stay behind with Kaido.
With the war going on outside the fortress, Maria received a call from King, one of the All-Stars, ordering that all of the Tobiroppo members cancel the search for Yamato and help stave off the invaders. Instead of going out to fight with the others, Maria and her underlings hid in the tatami room while Maria played music and sang. After capturing Sanji, she beat him until he called out for Robin through Caimanlady's special mask, which was Maria's plan all along. She wanted to lure Robin to the castle so that she could capture her and use her to read Kaido's Poneglyphs. However, Robin was able to avoid the traps Maria had laid out and use her Devil Fruit powers to push Maria away from Sanji while Brook freed him from the webs. Maria then received an order from Jack to say where she was, causing Maria to opt to fight Brook and Robin to kill time.
Much of Black Maria's abilities and fighting style are still unknown, as she never took part in a major fight up until now. She avoids unnecessary conflicts, preferring to play music and sing, in line with her courtesan design. That doesn't mean that she isn't a major threat to our One Piece heroes, though. She is a member of the Tobiroppo, after all.