Sengoku Driver

"Lock On!"

- Activation announcement

"(word/sound)! (fruit) Arms! (phrase)"

- Transformation announcement

"(word/sound)! (fruit) Squash/Au Lait/Sparking!"

- Finisher announcement

The Sengoku Driver (戦極（センゴク）ドライバー) is the transformation belt for the Armored Riders. It was invented by Ryoma Sengoku of the Yggdrasill Corporation.

Functionality
To transform, the user opens the lock on the Lockseed, then attaches it onto the Drive Bay (ドライブベイ). The Rider then closes the lock to secure it into the Lock On Arm (ロックオンアーム) and presses the Cutting Blade (カッティングブレード) knife down, which cuts open the Lockseed itself.

The Driver announces the Arms granted by the Lockseed, then a giant mechanical piece of fruit corresponding to the Lockseed used appears from a dimensional opening to the Helheim Forest above the user, and falls on top of their head. Once on the user, the fruit forms the helmet, materializes the suit, and the fruit disassembles to form the chestplate and pauldrons. If the Rider is already in the Helheim Forest, the fruit would just materialise above the Rider from energy in the same color as the Arms armor is in.

Even though all the Riders use a Sengoku Driver which share the same voice, they each have a unique Rider Indicator (ライダーインジケーター) plate on the wearer's left hand side. Each Indicator has different voice tones, as well as different phrases for each Lockseed being used. Each Sengoku Driver shown originally has a blank plate signifying that it is without a user; this is due to the fact that Sengoku Drivers are designed to synch with the first person that uses them, allowing only that individual to transform from thereon. However, a Yggdrasill Corporation employee was shown wearing a blank Driver with no Cutting Blades attached to the Driver, but the significance of this is unclear, though it could be linked to the fact that the Sengoku Drivers used by the Riders are prototypes and the ones the employees used are the mass-produced versions.

If the Sengoku Driver is destroyed, the Rider Indicator will disappear as well.

As shown, anyone who wears a Sengoku Driver, be it they be Riders or Yggdrasill Corporation employees, can turn immature Lockseeds into mature Lockseeds just by picking them from their stems.

Moreover, the Sengoku Driver can be combined with the Genesis Driver. This can be done by replacing the Rider Indicator with the Genesis Driver's Drive Bay with the Energy Lockseed. Currently, it's purposes are still unknown, but it is likely that it will power up the Rider.

When the Cutting Blade is pressed down between one and three times, a Rider can activate a certain ability:
 * Once: The Squash (スカッシュ) function can either initiate the Rider's Rider Kick or power up the Rider form's primary weapon for a finishing attack.
 * Twice: The Au Lait (オーレ) function gives extra power to the Squash function.
 * Thrice: The Sparking (スパーキング) function can either futher enhance a Rider's finishing attack to its full potential or convert the user's armor into its fruit form, which can be used as a shield before it reforms back into armor. For example, Gaim's Orange Arms has the potential to rotate at high speeds when using this function, making any attack thrown at it glance off at an awkward angle, leaving the attacker wide open for a counterattack, while Kurokage's Matsubokkuri Arms spins at an insane speed with his Kagematsu held out.

History
The Sengoku Drivers were invented by Ryoma Sengoku, a scientist of the Yggdrasill Corporation's R&D Branch. As per the company's plans, the first six would be prototypes distributed to the Beat Riders of Zawame City. This way, whenever a Beat Rider morphed and fought, the Driver would collect data that would be used further by the Corporation's R&D Branch. The data collected from the Sengoku Drivers would eventually culminate in the creation of the Genesis Drivers.

Owners

 * Kota Kazuraba/Armored Rider Gaim: Found by accident in the Helheim Forest. His Driver was initially purchased from Lock Dealer Sid by Yuya Sumii until the latter devoured a premature Lockseed and turned into an Inves.
 * Kaito Kumon/Armored Rider Baron: Purchased from Sid.
 * Mitsuzane Kureshima/Armored Rider Ryugen: 'Purchased' from Sid. (Used his status to convince Sid into "leaving behind" a Driver).
 * Takatora Kureshima/Armored Rider Zangetsu: Given to him by Ryoma Sengoku.
 * Hideyasu Jonouchi/Armored Rider Gridon: Purchased from Sid.
 * Ryoji Hase/Armored Rider Kurokage: Purchased from Sid. Broken due to a stray attack by Zangetsu.
 * Oren Pierre Alfonzo/Armored Rider Bravo: Confiscated from Sonomura of Team Red Hot. (After initial purchase from Sid)
 * Kamen Rider Bujin Gaim: Unknown

Portrayal
The voice of the Sengoku Driver, as well as the Musou Saber and the Lockseeds, is provided by Seiji Hiratoko (平床 政治).