Kazuma Kenzaki

Kazuma Kenzaki (剣崎 一真 Kenzaki Kazuma) is the main protagonist of the Kamen Rider Blade television series. He was chosen by the B.O.A.R.D. organization to use the sealed Category Ace of Spades to become Kamen Rider Blade (仮面ライダーブレイド Kamen Raidā Bureido). He has a good heart and believes in fighting to protect humanity.

History
At the age of 11, Kenzaki was orphaned when his family died in a house-fire. The powerlessness he felt would forever serve as the motivation to try and protect the defenseless, subsequently leading to being scouted by the Board Of Archaeological Research Department (otherwise known as B.O.A.R.D.). Because of his intelligence and exceptional survival instincts, he would eventually be promoted to field operative and the designated user of Rider System-02.

However, during assessment for the Rider System, Kenzaki displayed unusually high fusion coefficiency. Though this caused no immediate concern, as his levels maintained steady intervals. After being promoted to Rider status, Kenzaki would be partnered with fellow BOARD Rider and senior operative Sakuya Tachibana on assignment to hunt down three Undead over the next two months.

Eventually sealing the Bat Undead, Kenzaki meets a web-journalist named Kotarō Shirai, who begins investigating the Riders after witnessing Kenzaki carelessly changing back from his transformation. To lessen the risk of exposure (and to find a place to board after losing his apartment due to delinquent payments), Kenzaki made a deal with Kotarō: In exchange for information concerning the Riders, Kotarō would provide him a place to stay; being that his salary with BOARD was barely enough to make a living. But later that evening, disaster struck as BOARD HQ fell under attack from the Locust Undead.

With Tachibana's desertion and Karasuma--BOARD's president--nowhere to be found, Kenzaki and Shiori Hirose, one of BOARD's surviving staffers, set-up a new base of operations in Kotarō's home, using whatever equipment left undamaged during the Undead assault on BOARD HQ. Though operating at a limit capacity, Kenzaki, Hirose, and Kotarō successfully began tracking and sealing any active Undead in the area. But eventually Kenzaki redirects his focus on tracking down the rogue Tachibana, leading to a rivalry with a being named Chalice, who possesses similar powers & abilities to his Rider System. Their frequent encounters led to the discovery that Chalice was in fact a human named Hajime, but the origins of his powers and his motives remained a mystery at the time.

Kenzaki was later abducted by agents of a man named Isaka (the man responsible for Tachibana's strange behavior) who intended to used him in human/Undead fusion research. Kenzaki was forced into combat with the Trilobite Undead, and his fusion rate remained stable until Hajime appeared among his captors. Isaka witnessed a spike in Kenzaki's fusion ratio causing Hajime to transform and intervene, along with Tachibana. Hajime is revealed to be not human at all, but, in fact, the Joker Undead. Yet despite this knowledge, Kenzaki started to believe that there's some good in Hajime and not the monster he originally thought. However, once Griffa Undead was sealed, Hajime begins to lose control and his impulse as Joker comes forth with the Stone of Sealing creating an army of Dark Roaches to eliminate all humans. In the end, Kamen Rider Blade is the only one to combat him head on, both equal in power, intent on saving the Earth and Hajime from himself.

In the series ending, despite Hajime's pleas to Kenzaki to seal him once and for all to save the world, Kenzaki opted to sacrifice his humanity through excessive use of King Form in order to both save the world and Hajime, thus becoming a Joker himself. Hajime is allowed to keep his Human Spirit card to maintain his disguise and stays with the Kurihara family for the rest of his life; but still remembers what Kenzaki has done for him; for if he and Kenzaki cross paths, fate will step in and force them to fight. The show ends with an engine running and motorcycle tire tracks in the desert, most likely to be made by Kenzaki riding his Blue Spader away from humanity.

To stop the fusion and destruction of worlds, Tsukasa Kadoya, announced a tournament gathering all Riders to learn who was the strongest. Blade participated in the tournament fighting against Kamen Rider Stronger. Kazuma shows up in the World of the Rider War pointing out that their real enemy isn't Dai-Shocker, appearing just before his equivalent, Kazuma Kendate and the iteration of the World of Blade was destroyed by Apollo Geist's merging of the Rider Worlds. He transforms directly into his King Form to battle Decade, and manages to overpower the other Rider, before telling Asumu and Wataru that Decade will destroy their worlds, as well as Yusuke himself.

Some time later, in his regular Ace Form he teams up with Kamen Rider Ryuki to destroy Decade now in Violent Emotion's Form but Decade turns the tables on them by turning Kenzaki into Blade Blade to destroy Ryuki and later destroys him with his Final Attack Ride resulting in both Riders being turned into cards. He is later revived after Decade voluntarily lets himself be destroyed.

In a timeline alteration, after Shocker gained their victory, most Riders had been placed under their control with Leangle leading a small portion of their army. Kamen Rider Blade was claimed to be imprisoned by Tachibana during their infiltration to Shocker's base. However, it was revealed to be a lie as Tachibana was already an evil rider alongside Kenzaki. But soon Kenzaki alongside Tachibana, Hajime, and Mitsuki had their hearts changed despite still brainwashed after they couldn't accept how Shocker treated its own allies and aiding Drive.

After Takeshi Hongo and Hayato Ichimonji broke free from the Rider Robo, their brainwashing was fully destroyed. Once the timeline has been restored, Kenzaki returns to being the Navy Joker, and thus leaves humanity again. Blade is one of five dead riders who have been brought into another dimension, along with a still alive Emu Hojo. Though Kazuma is technically still alive as an Undead, he considers losing his humanity to be his "death".

300 years after these events, Kenzaki is trying to find a way to end his life after living a lonely existence for too long. He also seems to have become broken and somewhat insane as he seemingly couldn't remember why he chose to become an Undead in the first place.

Personality
After sacrificing his humanity to save Hajime and the world, Kenzaki had to leave his friends, therefore causing him to have a drastic personality change as he went from cheerful and hot headed to cold, calculating and merciless. He considers himself to have no more allies, and has also viewed himself to be technically "dead". His ruthlessness led him to even go so far as to attempt to kill Decade without any mercy. However, despite his cold personality, he still fights for justice as a Kamen Rider whenever he can, showing that there is still good left in him. Over the years, Tachibana would hear of a strange creature saving children and other people all throughout the world, showing that Kenzaki still continued to protect people even as a Joker.

Forms
Ace Form= Ace Form Ace Form (エスフォオム Esu Foomu) is the default transformation of Rider System-02. The transformation harnesses the Beetle Undead's DNA cultured from the ♠A: Change Beetle Rouze Card and, via the Blay Buckle, initiates a fusion with Kazuma Kenzaki into Kamen Rider Blade. Jack Form (ジャツクフォオム Jakku Foomu) is a combat extension of the Rider System which harnesses the power of Category Jack Rouse Cards (in the case of Blade, the ♠Jack: "Fusion Eagle") via the Rouse Absorber. Initiating Blade's Jack Form transmogrifies the Rider Armor with the attributes and characteristics of the Eagle Undead DNA with the ♠J: "Fusion Eagle" card, as well as enhancing Blade's combat perimeters. King Form (キングフォーム Kingu Fōmu) is the ultimate combat extension of the Rider System. Using the Rouse Absorber, this transformation is initiated using the ♠K's "EVOLUTION KING" effect in conjunction with the ♠Q's "ABSORB QUEEN" effect. The King Form addresses many issues with Blade's combat capabilities such as defense. In this form, Blade's blue shade turns black, he gains shining gold armor, and he gains gold slabs on his legs and arms, along with gold shoulder pads, each representing each Spade Undead (The Change Beetle card is represented on Blade's belt). Joker (ジョーカー Jōkā) is a mutation caused by excessive usage of Blade's King Form. During the final episodes, he began using King Form excessively to the extent that he would use it right from the start of a fight to ward off mere Darkroaches, even if it put a huge strain on his body. It was revealed in the final episode that he did so deliberately to lead the Battle Fight into a stalemate, by discarding his humanity and transforming himself into a Undead permanently, so as to allow Hajime to live as a human and saving the world at the same time. Because of this form, Kenzaki can currently use Blade's powers more efficiently as well as gained the standard powers of a Joker Undead.
 * Rider Height: 201cmKamen_Rider_Blade_Ace_Form.png
 * Rider Weight: 101kg
 * Ability Perimeters
 * Punching Power: 2.8 tons
 * Kicking Power: 4.8 tons
 * Max Jump Height: 33m
 * Maximum Running Speed: 100m/5.7s
 * -|Jack Form= Jack Form
 * Rider Height: 201cmBlade-BladeJack.jpg
 * Rider Weight: 101kg
 * Ability Perimeters
 * Punching Power: 3.5 tons
 * Kicking Power: 5.5 tons
 * Max Jump Height: 133m
 * Maximum Running Speed: 100m/4.6s
 * -|King Form= King Form
 * Rider Height: 201cmBlade-BladeKing.jpg
 * Rider Weight: 131kg
 * Ability Perimeters
 * Punching Power: 4.5 tons
 * Kicking Power: 7.0 tons
 * Maximum Jump Height: 25m
 * Maximum running speed: 100m/6.6s
 * -|Joker= Joker
 * Height: 219 cm
 * Weight: 116 kg
 * Ability PerimetersJokerUndead.jpg
 * Punching Power: 8.0 tons
 * Kicking Power: 8.5 tons
 * Maximum Jump Height: 60m
 * Maximum running speed: 100m/3.5s

Trivia

 * It is notable that Kenzaki is one of the few known people to have defeated Tsukasa as Decade in combat.