
She's occurred often enough in the Birds of Prey that you could safely consider her a member of the team. Unlike a lot of the other main Outsiders characters she's also made a lot of appearances in other series, as her overall design and persona are clearly just very cool. She wasn't a founding member of the 2003 Judd Winick redesign of the team, but joined them in issue #34 after the one year later timeskip, which I believe makes her the character that has appeared in more iterations of the Outsiders than any other.
KATANA ARROW VS KATANA SUICIDE SQUAD SERIES
The bulk of Katana's appearances are in all of the various Outsiders series over the years. Her husband and children were killed, leaving her with the sword and a vendetta against the Yakuza. She married Maseo and had two children before Takeo, who had become a gangster, attacked them with a mystic, soul-sealing sword. While training under her teacher, Tadashi, she was courted by two brothers, Maseo & Takeo. She could pretty easily have been a much less compelling character and instead have just been a series of cringy tropes (In fact, there are certainly moments in her original appearances that don't exactly hold up) but thankfully she was granted a cool, very personal story that gave her purpose outside of her cultural identity. Katana's whole story and costume are pretty obviously the result in the increased interest in Japanese culture in the early 80s after the release of the NBC miniseries Shogun. They debuted in DC Sampler #1 in 1983, but of course their actual story begain in Batman and the Outsiders #1. It might not have made her a standout character like Harley or Deadshot, but even one more scene in Suicide Squad that showed off what an intriguing vigilante Katana can be would have been worthwhile and made for a more enriching viewing experience.Katana was one of the original characters invented to join the Outsiders, a new team for Batman to lead. Similar to Leto's Joker, who had a ton of material left on the cutting room floor, Katana might have overall been more memorable to audiences had this scene been included in the movie. wanted to cut out much of the dark atmosphere that Ayer had built up in his cut of the film. With more and more information coming to light on just how different the theatrical version is from Ayer's original vision, there's a chance that the possession scene could have given her character a bit more heart in execution.
KATANA ARROW VS KATANA SUICIDE SQUAD MOVIE
Even with this additional scene, though, it wouldn't necessarily justify her presence in the movie or give her a proper story arc that taps into her nuanced backstory. Katana is frequently depicted as one of the best hand-to-hand fighters in the DC Universe, and the theatrical cut of Suicide Squad doesn't give her a chance to shine, so having a scene where Katana squares off against the entire Suicide Squad alone would have really put her talents into perspective. This addition would have given her a larger role in the film and utilized her unique status as a fighter in an exciting way. However, we now know that Ayer's original plan for her involved Katana being possessed by Enchantress later in the film and turning on her teammates.

In the released version of the film, Katana accompanies Rick Flag on the Squad's mission and acts as a "bodyguard" of sorts, but doesn't end up doing much within the context of the movie's plot. The events inspired her to use the weapon to fight crime and, taking up the namesake Katana, Tatsu traveled to America where she became entangled with several established DC superheroes, including Batman and the Outsiders.

She hunted down and defeated her husband's killer, taking the sword only to discover it was now possessed by the spirit of her husband. After her husband was murdered by his own brother (a high-ranking gangster in the Yakuza), using a mythical blade known as the Soultaker sword, Tatsu Yamashiro vowed revenge. Because of her comic-accurate backstory, Katana is depicted as one of the most intriguing and unique characters in the movie.
