Takatora Kureshima is Kamen Rider Zangetsu, later becoming Kamen Rider Zangetsu Shin.
He is Mitsuzane Kureshima's older brother, who was a project leader in the Research and Development branch of the Yggdrasill Corporationuntil he finds out the company has been compromised, usurped by Ryoma. This causes him to team up with his old enemy, Kouta Kazuraba. He is the main antagonist in the first half of the series, eventually being replaced his younger brother Mitsuzane, and eventually Kaito Kumon.
At some point prior to the beginning of the story, Takatora was instrumental in testing the early prototypes of the Sengoku Driver. Though he suffered physical harm and scars from setbacks, he uses the Melon Lock Seed and a finalized Sengoku Driver prototype to become Kamen Rider Zangetsu to deal with the Inves in Helheim Forest. Despite his questionable methods, his intentions are well-meaning, proven from the fact that he instructed Ryoma to lower the specs of the Sengoku Driver to facilitate easier mass production, so to save more people, instead of hoarding power to himself.
Takatora is seen throughout the Beat Riders Saga as the protector of the Helheim forest, protecting his men as they forage into the forest to harvest the Helheim fruits. During one of these expeditions, he battles Gaim and teaches him the cruelty of reality and that the Sengoku Driver isn't a toy.
During the events of the Kamen Rider × Kamen Rider Gaim & Wizard: The Fateful Sengoku Movie Battle, Takatora finds that three of the Sengoku Driver users have gone missing. During his search, he finds a Crack that leads to the Sengoku Period world, with Mai following him behind without him realizing it. Takatora accidentally aids Bujin Gaim, causing Bujin Double to be defeated, before realizing that Bujin Gaim isn't his world's Gaim. Takatora picks up the Joker Memory, the remnants of Bujin Double. Later, after Bujin Fourze was defeated, he picks up the Rocket switch. When he encounters Ryugen, he gives him the Suika Lockseed to use. During the climax of the movie, Takatora appears once more as Zangetsu, aiding Gaim, Baron, and Wizard against Bujin Gaim and the Nephenthes Inhumanoid. Despite Nitoh and Mitsuzane being saved, Takatora fails to pay attention that the young man with the Sengoku Driver is his brother due to Takatora focusing on Gaim, and focus on saving the alternate world from Bujin Gaim's reign. When The Mysterious Girl appears, he realizes that the remnants of the Bujins resonate with the Lockseeds that the girl left in her wake, creating the Fourze, OOO, Double, and Wizard Lockseeds. Together with the Armored Riders in their respective Rider Arms along with Beast Hyper, they destroy the Nephenthes Inhumanoid with a combined Rider Kick. In the aftermath, Takatora misses Mitsuzane once again, seeing only Kouta pass by as Takatora, Ryoma, and Yoko all containing an Energy Lockseed and a Genesis Driver.
Takatora later appears during the Lockseed gathering game, causing all 7 prototype Sengoku Drivers to appear in the forest. Takatora defeats Gridon, Baron, and Bravo without breaking a sweat, but in a rage, destroys Kurokage's Sengoku Driver by accident. He returns to Headquarters displeased that Gaim saved his men, calling him street trash.
After the development of the Genesis Drivers and his new transformation into Kamen Rider Zangetsu Shin, Takatora deems the Beat Riders to have outlived their usefulness. After learning that Mitsuzane was made an Armored Rider behind his back, Takatora shows his younger brother the ruins in Helheim Forest to convince him to help him for the greater good. When meeting Kouta and showing him the ruins, Takatora sees the same ideals he once embodied in the youth and it only makes him more adamant to crush Kouta's spirit. He succeeds when he reveals to Kouta that in his first battle as Armored Rider Gaim, he killed his friend Yuya Sumii who had been transformed into the White Tiger Inves. However, Takatora later is shocked that the revelation has the opposite effect on Kouta, who destroys Yggdrasill's Scalar System.
After Mitsuzane reports to the group that DJ Sagara is helping Kouta, concealing the full story of the Overlord Inves, Takatora does not believe these turn of events at first. However, Takatora learns the truth when he confronts one of the Overlords leading an attack on the research team with Kouta informing him of how the type of Inves may be instrumental in stopping Helheim Forest's expansion. Seeing a way to stop the invasion without massive sacrifices, he decides to ally with Kouta to stop the Overlords. However, Takatora is oblivious to the fact that Ryoma's group is conspiring against him. This becomes Takatora's downfall as he is usurped by Ryoma's group and loses his Genesis Driver while being subsequently thrown off a cliff. Eventually, he was rescued by the Overlord king, Rosyuo, as he begins to learn about their origins.
Over Lord Saga
After Mitsuzane reports to the group that DJ Sagara is helping Kouta, concealing the full story of the Over Lord Inves, Takatora does not believe these turn of events at first. However, Takatora learns the truth when he confronts one of the Over Lords leading an attack on the research team with Kouta informing him of how the type of Inves may be instrumental in stopping Helheim Forest's expansion. Seeing a way to stop the invasion without massive sacrifices, he decides to ally with Kouta to stop the Over Lords. However, Takatora is oblivious to the fact that Ryoma's group is conspiring against him. This becomes Takatora's downfall as he is usurped by Ryoma's group and loses his Genesis Driver while being subsequently thrown off a cliff. Eventually rescued by the Over Lord king, Rosyuo, Takatora learns the origins of the Femushinmu. Now realizing Ryoma's ambition, he realizes what Ryoma meant by him never understanding what he worked for. To his dismay about humanity being able to be saved, Rosyuo declares that humanity is foolish and will not obtain the Forbidden Fruit to repeat the tragedies that happened to his civilization.
While trying to find more answers about the Helheim's origins, especially Rosyuo's deceased wife, DJ Sagara later appears, informing that Demushu has recklessly struck the city, with Rosyuo unleashing the forbidden fruit he guarded from his hand, taking some seeds and turned them into the Kiwami Lockseed, much to Takatora's surprise, as DJ Sagara leaves to find a rightful person to be its guardian. He is soon spotted by Sid, and is about to be killed. Luckily Rosyuo protects him and kills Sid, but Takatora is shocked in horror at witnessing it. Shortly before finding out the Over Lords are setting their ways to invade Earth, Takatora takes Sid's hat as a keepsake shortly before Redyue takes it from him.
Though a ruthless realist, Takatora still loves his family and spoils his younger brother, and especially cares about Mitsuzane's education. He is the most experienced and most powerful Armored Rider to date. In order to teach Gaim a lesson, who entered the Forest without his permission, without knowing that he's only looking for his friend, he brutally attacks him despite Kouta having no intention to fight him to make his point - that power given by the Lockseeds and Sengoku Driver is no game, letting Kouta go after clearly being the winner.
Despite his sense of realisim, he can show signs of arrogance and his wealthy upbringing has mildly affected his view of the world. He sometimes refers to the other Armored Riders as "street trash" that are beneath him and not worthy of his attention, the exception being if they directly interfere with his plans.
He also seems to have a bit of a temper when pressured, as seen when Kurokage provokes him while he was trying to reach his staff to rescue them from the Inves swarm. This caused him to have an angry outburst and unintentionally damage Ryoji's Sengoku Driver with a furious blow of sword slashes.
As stated by him back when he first encountered Gaim, he knows the Lockseeds carry a dangerous disease, which is also seen when he tries to warn Hase not to eat the immature fruit.
Under his ruthless realist personality shows that Takatora does have hidden feelings, grieving that he is only able to save about a billion of the Earth's population. More of this side is shown when he takes care of Oren after Oren takes a hit that disrupts his transformation as he falls into his arms. In addition, he finally lightens up, handshaking Kouta and thanking him for giving him an alternative means to save humanity rather than culling the world's population through Project Ark.