|This article is about a/an weapon in Kamen Rider Build.|
The Transformation Frost Fist Grease Blizzard Knuckle (変身凍拳グリスブリザードナックル Henshin Kō Ken Gurisu Burizādo Nakkuru), is a variant of the Cross-Z Magma Knuckle used by Kamen Rider Grease to transform into Kamen Rider Grease Blizzard by inserting it, loaded with the North Blizzard Fullbottle, in the Build Driver. Before it was completed, it was known simply as the Blizzard Knuckle (ブリザードナックル Burizādo Nakkuru). Cross-Z Magma used this unfinished version as a secondary personal weapon before returning it to Sento, who then completed it and gave it to Grease.
The Grease Blizzard Knuckle is composed of the following parts:
- GBZ Glacial Charger (GBZグレイシャルチャージャー GBZ Gureisharu Chājā) - The energy generation unit built into the Grease Blizzard Knuckle, it is responsible for generating all of the energy for transformation and finishing attacks. During transformation, it converts the ingredients of the inserted North Blizzard Fullbottle into the ice-crystal like Variable Ice (ヴァリアブルアイス Vu~ariaburu Aisu). Additionally, it can freeze the captured Transgel Solid inside of the North Blizzard Fullbottle, allowing its component amount to increase by four times.
- Northern Force Knuckler (ノーザンフォースナックラー Nōzan Fōsu Nakkurā) - The freeze grinding unit mounted to the front of the Knuckle. The surface is composed of stiffened parts made from melted components of the Robot Sclashjelly, and is further powered via a vibration unit built into the Knuckle, increasing damage capability. When unleashing a charge attack, light energy is emitted from the four ducts.
- Robotic Igniter (ロボティックイグナイター Robotikku Igunaitā) - The button of the Knuckle that is engraved with Grease's logo. By pushing the button, the GBZ Glacial Igniter is activated, and rapid generation and compression of the light emission energy is executed. Luminous energy is emitted from the duct of the striking face at the same time as releasing the button, causing a large explosion with the impact of the attack. If a Fullbottle is loaded to the Fullbottle Slot, a special charge attack with its characteristics can be made, powerful enough to disable an enemy with a single strike.
- Fullbottle Slot (フルボトルスロット Furubotoru Surotto) - The slot where a Fullbottle is inserted. It has the role of activating the Transgel Solid in the loaded bottle with a special pulse and taking it inside.
- GBZ Knuckle Transer (GBZナックルトランサー GBZ Nakkuru Toransā) - The transformation button to use when transforming from Knuckle to Adapter mode. After loading the North Blizzard Fullbottle in the slot, lifting the grip while pressing the button activates the transformation system. At this time, the GBZ Glacial Charger is activated, and a large amount of Variable Ice is rapidly generated.
- Blizzard Bray Grip (ブリザードブレイグリップ Burizādo Burei Gurippu) - The grip part of the knuckle. The motion detection system is carried and optimizes the behavior at the time of attack by recording and analyzing the behavior of the enemy and the habit of the user.
- GBZ Knuckle Connector (GBZナックルコネクタ GBZ Nakkuru Konekuta) - The connection terminal of the Grease Blizzard Knuckle which juts out of the bottom. When the Grease Blizzard Knuckle is inserted into the Build Driver, the Northern Force Knuckler will split in half, opening to the left and right and revealing the concealed North Blizzard Fullbottle. Afterwards, a special ladle called the Ice Ride Builder (アイスライドビルダー Aisu Raido Birudā) forms, which is directly connected to the GBZ Glacial Charger, and proceeds to dump the Variable Ice over the user. The Variable ice reacts to special pulses emitted by the Driver, allowing it to form suit components.
Sento created the Blizzard Knuckle to counteract Evolto's powers. During Sento's trials, Ryuga Banjo attempted to use it to transform, but failed. Sento takes the Blizzard Knuckle and goes to face Evolto alone. However, he was being followed by Gentoku, Kazumi, and Banjo, who took back the Blizzard Knuckle. In the ensuing fight with Evolto, Banjo uses the Blizzard Knuckle with the Silver Dragon Fullbottle to unleash a devastating attack on Evolto, allowing Sento to land the final hit.
In preparation for the final battle with Evolto, Kazumi asked Sento to create a new power-up item since he felt that Grease wasn't strong enough to keep up with Build and Cross-Z. Sento revealed that was the reason he created the Blizzard Knuckle in the first place, but he wasn't able to give it to Kazumi because he and Gentoku had left nascita as part of a plan to raise their Hazard Levels. However, Kazumi's elevated Hazard Level meant that using the Knuckle to transform would almost certainly kill him, so Sento made him promise to only use it as a weapon, something Kazumi considered a moot point since he didn't have a Build Driver.
During the assault on Pandora Tower, the Kamen Riders were confronted by copies of the Hokuto Three Crows created by Evolto to halt their progress. Grease sent the other Riders ahead, but found himself unable to fight effectively thanks to the copies using his feelings for the real Three Crows against him. Pushed into a corner, Kazumi pulled out Shinobu Katsuragi's Build Driver (which he had secretly taken from Sento's lab before they left) and, apologizing to Sento for breaking his promise, used it to transform into Grease Blizzard. This would later be his undoing as Kazumi died after using it, since his Hazard Level increased far more than his body could handle.
After Kazumi was revived in the New World, however, the use of this Knuckle is no longer able to kill him as his body is capable to maintain his current Hazard Level. Thanks to the Phantom Liquid soaking into him, he can maintain the form for a longer time, and didn't suffer from the drawbacks of the weapon.
The user inserts the North Blizzard Fullbottle into the Fullbottle Slot on the Grease Blizzard Knuckle, flips the Blizzard Bray Grip to the top after pressing the GBZ Knuckle Transer, and inserts the device into the Build Driver, causing the Northern Force Knuckler to split down its middle and expose the inserted Fullbottle. After cranking the Vortex Lever, the Ice Ride Builder forms and submerges the user in liquid Variable Ice, which then freezes. The Ice Ride Builder then breaks the Variable Ice, revealing Grease Blizzard.
Grease or Cross-Z can use the Blizzard Knuckle by itself as a knuckleduster weapon. In this mode, pressing the Robotic Igniter without a Fullbottle inserted will boost the weapon's power and enable it to unleash a charged attack. This attack is several times more powerful when Grease is already in Grease Blizzard form.
The finisher accessed by the Build Driver depends on how many times the Vortex Lever is cranked.
By cranking the Vortex Lever a few times and the Grease Blizzard Knuckle announces "Single Ice!", Grease Blizzard can perform the Glacial Attack (グレイシャルアタック Gureisharu Atakku): Grease creates a large Variable Ice construct of the GBZ Demolition One that spins before he grabs the enemy with it and crushes them.
By cranking the Vortex Lever many times until the Grease Blizzard Knuckle announces "Twin Ice!", Grease Blizzard can perform the Glacial Finish (グレイシャルフィニッシュ Gureisharu Finisshu) finisher, and it has two variatins.
- Grease produces ice from each of the GBZ Ice Pack Shoulder (GBZアイスパックショルダー GBZ Aisu Pakku Shorudā) in order to propel himself forward and performs a flying kick covered in light blue energy. The kick freezes enemy the moment it connects before breaking through it, completely destroying the target.
- Grease uses the GBZ Demolition One to produce a mist that freezes the target's lower body before jumping into the air and performing a flying Rider Kick covered in ice.
By plugging a Fullbottle into the top of the Blizzard Knuckle before pressing the Robotic Ignitor, Cross-Z or Grease can perform the Glacial Knuckle (グレイシャルナックル Gureisharu Nakkuru).
- Silver Dragon: Cross-Z Magma punches the enemy as the incomplete Blizzard Knuckle creates an energy projection of a blizzard that freezes the target before launching them away.
- The use of the weapon can be seen as an inverse callback to the actor's past role, being a weapon that triggers a transformation when inserted into a device, but carries a dangerous risk on the human body if used recklessly.
- Given the nature of the weapon and the similar design to the Cross-Z Magma Knuckle and Magma Ride Builder, its use would suggest it's based on a chemical vat. Just like a vat for molten materials for smelting, the weapon and Ice Ride Builder could be based on one that specializes in cold/frigid materials.
- Kamen Rider Build