|This article is about a/an weapon in Kamen Rider Build.|
The Valve Rotator Steam Blade (バルブ回転スチームブレード Barubu Kaiten Suchīmu Burēdo) is a weapon wielded by users of the Transteam Gun or the Nebulasteam Gun. It combines with the Transteam Gun to form the Steam Rifle (スチームライフル Suchīmu Raifuru) or the Nebulasteam Gun to form the Nebulasteam Rifle (ネビュラスチームライフル Nebyura Suchīmu Raifuru).
- Overheat Blade (オーバーヒートブレード Ōbāhīto Burēdo) - The yellow bladed portion of the Steam Blade. An inbuilt heating unit can change its surface temperature, allowing the user to melt objects upon contact.
- Steam Change Valve (スチームチェンジバルブ Suchīmu Chenji Barubu ) - The red valve in the middle of the Steam Blade, it allows the user to change between Ice, Elek or Devil Steam for attacks.
- Tri-Attack Trigger (トリアタックトリガー Toriatakku Torigā) - The trigger of the Steam Blade. After changing the Steam Change Valve to the desired steam attack, pressing the Tri-Attack Trigger will activate the finisher.
- Transtock Grip (トランストックグリップ Toransutokku Gurippu) - The grip of the Steam Blade, it seperates from the rest of the weapon when combining with the Nebula/Transteam Gun. It is excellent at absorbing impacts during attacks. When combined with the Nebula/Transteam Gun, it serves as a counterweight so as to prevent the weapon's trajectory be affected by the weight of the front blade.
- End Shot Muzzle (エンドショットマズル Endo Shotto Mazuru) - The gun muzzle of the Nebula/Steam Rifle, it is capable of shooting out bombardment bullets called Trans Burette (エンドショットマズル Toransu Byuretto) or special light bullets containing various types of steam, inflicting great damage upon the target.
- Long Snipe Scope (ロングスナイプスコープ Rongu Sunaipu Sukōpu) - The scope mounted on the Nebula/Transteam Gun, it has an inbuilt computer system which measures distance to the target, wind speed, air density, etc. and uses it to pinpoint accurate trajectory and perform automatic correction of sighting if necessary. Using the Long Snipe Scope, it is possible to snipe up to 3km with pinpoint precision.
The Steam Blade splits at the handle and its blade connects to the front of the Transteam Gun/Nebulasteam Gun, while the handle connects to the back of the Gun to form the Steam Rifle.
The Steam Blade's valve turns in both Blade Mode and Rifle Mode to change attack types.
- Elek Steam (エレキスチーム Ereki Suchīmu), has two variations:
- Night Rogue or Blood Stalk shoot electricity at the enemy.
- Night Rogue or Blood Stalk perform a series of electricity slashes at the enemy causing them to paralyze.
- Ice Steam (アイススチーム Aisu Suchīmu): Night Rogue or Blood Stalk perform a series of ice slashes at the enemy causing them to freeze.
- Devil Steam (デビルスチーム Debiru Suchīmu): Night Rogue or Blood Stalk use the Steam Blade to emit steam with a Nebula Gas-compound that can turn humans into Smash or make a Smash grow to gigantic proportions. In Rifle mode it fires a steam bullet which will home in on the target and directly injects them with Nebula Gas when it hits them.
The Steam Rifle has 2 shooting finishers: Steam Shot (スチームショット Suchīmu Shotto) with a Faust Fullbottle and Steam Attack (スチームアタック Suchīmu Atakku) with a normal Fullbottle.
The Nebulasteam Rifle's finisher is the Funky Shot (ファンキーショット Fankī Shotto) with a Fullbottle or a Gear.
- Bat: Night Rogue shoots a powerful steam blast at the enemy.
- Cobra: Blood Stalk shoot a purple cobra energy blast that detonates upon impact.
- Rocket: Blood Stalk shoots a powerful blast attack that takes the form of a rocket. The rocket flies around the enemy before coming to the ground for an explosion.
- Rabbit Evolbottle: Evol runs extremely fast in a circle around the enemy and fires at them with the Steam Rifle.
- Gear Engine: Engine Bro's shoots an energy-like engine bolt at the enemy.
- Elek Steam: Remocon Bro's shoots an electric energy-like engine bolt at the enemy.
- Crocodile Crack: Rogue fires a Cruncher Fang projection towards his target.
- Bat: Remocon Bro's shoots a purple bat energy blast that detonates upon impact.
- Phoenix: Rogue fires a flame blast towards his target.
- Evoltic Attack (エボルテックアタック Eborutekku Atakku):
- MadRogue fires a steam projectile covered in purple energy from the Nebulasteam Rifle.
- MadRogues unleashes two energy slashes from the Steam Blade that travel through the air and follows them up with sustained fire from the Nebulasteam Gun.
- The Steam Rifle's design resembles the real-life Mk 14 Enhanced Battle Rifle, otherwise known as the M14 EBR.