Hazard Trigger

The Hazard Trigger (ハザード トリガー) is a turbocharger-like device that allows Kamen Rider Build to upgrade each Best Match into a Super Best Match (スーパベストマッチ).

Functionality
"Like I thought, they went out of control. Wanna know how you can stop their power? The forbidden item created by Katsuragi... Hazard Trigger."

- Blood Stalk revealing the Hazard Trigger to Sento

According to Blood Stalk, the Hazard Trigger is a forbidden Item created by Takumi Katsuragi. This device allows the user to boost their Hazard Levels to extraordinary levels, therefore strengthening them even more. However, similar to the Sclash Driver, using it has side effects - when used with a Build Driver, prolonged usage would cause the stimuli to overwhelm the user's brain, thus they will lose their sentience and regress to a berserk-like state, attacking everyone and thing in its sight. If a Smash uses it, they will die upon being defeated.

According to Blood Stalk, if one's Hazard Level is high enough, they could possibly overcome the side effects. . This is supported by the fact that Sento is able to keep himself consciously intact longer the more he used it.

After several tests performed by both Sento and Utsumi, Sento creates a Fullbottle-shaped kill switch that when used, will destroy the Hazard Trigger. If the Trigger was being used by someone during the kill process, it will subsequently kill its user as well.

Ultimately, the Hazard Trigger would be outclassed by the Crocodile Crack Fullbottle, centrepiece of the new Kamen Rider Rogue system used by Gentoku Himuro.

Design
The Hazard Trigger is composed of the following parts:
 * Force Ride Meter (フォースライドメーター): The circular meter located at the centre of the Hazard Trigger. It measures the fighting ability of the user, and the higher the reading, the more powerful the attacks are. However, if the meter reaches the dangerous zone during battle, the user will go beserk due to massive amounts of stimuli, causing a loss of sense of self.
 * Progress Tank (プログレスタンク): The handle sticking out of the Hazard Trigger. It is filled with an enhancement agent named Progress Vapor (プログレスヴェイパー), a reinforcement agent developed from Nebula Gas components, and has the ability to raise Hazard Levels. This agent reacts with Transgel Solid inside of Fullbottles and turns them into metallic components, During transformation, the Progress Vapor is poured through the Hazard Ride Builder (ハザードライドビルダー) and processed into reinforced equipment along with the contents of the Fullbottles, creating the Hazard Suit.
 * BLD Ride Connector (BLDライドコネクター): The grey part sticking out of the bottom of the Hazard Trigger. It connects the trigger to the BLD Ride Port (BLDライドポート) top of the Build Driver. Responsible for developing the Hazard Ride Builder.
 * Security Clear Cover (セキュリティクリアカバー): The clear cover concealing the BLD Hazard Switch, preventing accidental pressing during battle.
 * BLD Hazard Switch (BLDハザードスイッチ): The blue button on the Hazard Trigger. Pressing it activated the Hazard Trigger. Once transformed, pressing it again allows access to Overflow (オーバーフロー) Mode, raising the Hazard Level again and raising fighting ability. Said fighting ability is potent enough to inflict fear upon enemy and ally alike.

Kamen Rider

 * Kamen Rider Build
 * RabbitTank Hazard Form (Build Episodes 20-23)
 * SmaphoWolf Hazard Form (Raising the Hazard Level ~7 Best Matches~)
 * HawkGatling Hazard Form (Build Episode 22)
 * KaizokuRessya Hazard Form (''Build Episode 24)

Smash

 * Castle Hazard Smash (Build Episodes 19-21, 23-24)
 * Stag Hazard Smash (Build Episodes 19-21)
 * Owl Hazard Smash (Build Episodes 19-21, 23)