This article is about a/an villain form used by several identities in Kamen Rider Build.
KRBu-Engine Bros

Engine Bro's (エンジンブロス Enjin Burosu) is a Kaiser System transformation assumed by the following characters:


Nebula Hell Bro's
Nebula Hell Bro's

Nebula Hell Bro's

Nebula Hell Bro's (ネビュラヘルブロス Nebyura Heru Burosu) is the basic body of the Kaiser with no gears attached, though it is typically bypassed altogether in the transformation into Engine Bro's.

Engine Bro's
KRBu-Engine Bros

Engine Bro's

"Gear Engine! Funky! (Rock music, engine revving) Engine Running Gear!"
―Transformation announcement[src]


  • Height: 203.0 cm.
  • Weight: 103.5 kg.

Ability Perimeters:

  • Punching Power: 30.2 t.
  • Kicking Power: 37.2 t.
  • Maximum Jump Height: 48.6 m.
  • Maximum Running Speed: 100 m. per 1.7 sec.

Engine Bro's (エンジンブロス Enjin Burosu) is the white Kaiser, transformed into by inserting the Gear Engine into the Nebulasteam Gun.

Engine Bro's possesses the strength to rival Kamen Rider Grease, Kamen Rider Cross-Z Charge, and Kamen Rider Build RabbitTank Sparkling Form, only beginning to struggle with Build's RabbitTank Hazard Form. Engine Bro's, however, is not without a weakness. Being based on an engine, he can easily be damaged with water-based attacks.

Remocon Bro's and Engine Bro's share a single Nebulasteam Gun and Steam Blade. In battle, Remocon Bro's usually wields the Nebulasteam Gun while Engine Bro's usually wields the Steam Blade.

Engine Bro's is composed of the following parts:

  • Engine Bro's Head (エンジンブロスヘッド Enjin Burosu Heddo) - The helmet.
    • Engine Dark Visor (エンジンダークバイザー Enjin Dāku Baizā) - The engine-like visor covering the entire left side of the helmet. It is a shock-resistant frame that has been stretched to demonstrate high defensive capabilities against physical attacks.
    • Grudge Signal (グラッジシグナル Gurajji Shigunaru) - The white gear on the forehead. When the user's level of anger surges, the chest-mounted Nebula Generator is operated at a higher rate, resulting in increased combat ability.
    • Dusk Seeker Eye (ダスクシーカーアイ Dasuku Shīkā Ai) - The red eye. It is a highly sensitive sensor that can detect a moving body's reaction and heat sources. It is also capable of night vision, chemical detection and can examine enemy traces.
    • EB Side Blade (EBサイドブレード EB Saido Burēdo) - The antenna. It can collect information in realtime to grasp the capabilities of enemies. It also manages the body's condition and automatically repairs any broken or damaged areas.
    • EB Face Guard (EBフェイスガード EB Feisu Gādo) - A defensive gear located around the mouth and chin area. It can release a special wave to weaken an enemy's energy attack, minimising damage.
    • Air Face Duct (エアフェイスダクト Ea Feisu Dakuto) - Exhaust devices/air filters located around the chin area. When air is breathed in, harmful substances are removed. It can discharge any taken toxins back into the environment.
  • Cog Chest Armor (コグチェストアーマー Kogu Chesuto Āmā) - The robust chest armor. It has a built-in Nebula Generator (ネビュラジェネレーター Nebyura Jenerētā) which can produce special steam that enhances Remocon Bro's' fighting ability by temporarily speeding up movements to increase attack power.
  • Gear Steam Shoulder (ギアスチームショルダー Gia Suchīmu Shorudā) - The right shoulder armor. It optimises arm movement to increase attack efficiency. It can scatter colored gas through armor gaps.
  • EB Unlimited Suit (EBアンリミテッドスーツ EB Anrimiteddo Sūtsu) - The shockproof bodysuit. Along with protecting the wearer’s body, there is a limiter installed that can be released to bring out full physical ability.
  • Punishment Arms (パニッシュメントアーム Panisshumento Āmu) - The arms. They combine power and speed, and is capable of rapid punches and elbow blows.
  • Gear Torque Gauntlet (ギアトルクガントレット Gia Toruku Gantoretto) - A special device mounted on the right forearm. It can generate special energy cutters in the form of gears to launch at enemies.
  • Dominate Gloves (ドミネイトグローブ Domineito Gurōbu) - The reinforced hands. It's shape makes it suitable for melee attacks, and is capable of thrusting attacks thanks to its sharp claw-like fingertips.
  • Puishment Legs (パニッシュメントレッグ Panisshumento Reggu) - The legs. They combine power and speed, and is capable of continuus kicks and high-knee kicks.
  • Metal Knee Bat (メタルニーバット Metaru Nī Batto) - The knee armor. Optimises leg movement to improve their speed.
  • Aidron Shoes (アイドロンシューズ Aidoron Shūzu) - The feet. They are good at quick and quiet movements, allowing Engine Bro's to quickly sneak up to enemies. A special steam can be dispersed from the tips to create afterimages, disorienting opponents.

Engine Bro's has 3 different finishers:

  • Nebulasteam Gun finisher:
    • Funky Drive (ファンキードライブ Fankī Doraibu): Engine Bro's channels the power of a Gear and performs a powerful blast attack.
      • Gear Engine:
      • Gear Remocon:
    • Funky Attack (ファンキーアタック Fankī Atakku) Engine Bro's channels the powers of a Fullbottle and performs a powerful blast attack.
  • Nebulasteam Rifle finisher:
    • Funky Shot (ファンキーショット Fankī Shotto): Engine Bro's channels the power of a Gear or Fullbottle and performs a powerful blast attack.
      • Gear Engine: Engine Bro's shoots an energy-like engine bolt at the enemy.
      • Gear Remocon:

Appearances: ROGUE Episode 3, Build Episodes 23-26, 29-30, 32, 37-38, 47




  • Steam Blade - Standard sidearm weapon. Can combine with the Nebulasteam Gun to form the Nebulasteam Rifle. Shared with Remocon Bro's.


Sento Kiryu (Takumi Katsuragi) - Ryuga Banjo - Kazumi Sawatari - Gentoku Himuro - Evolto - Nariaki Utsumi - Shinobu Katsuragi - Kengo Ino - Killbus - Keiji Uraga
Transformation Gear
Fullbottles - Build Driver - Transteam Gun - (Great) Cross-Z Dragon - Sclashjellies - Sclash Driver - Hazard Trigger - Nebulasteam Gun - Cross-Z Magma Knuckle - Evol-Driver - Evol-Trigger - Grease Blizzard Knuckle - Killbuspider - Grease Perfect Kingdom
Drill Crusher - Hawk Gatlinger - 4Koma Ninpoutou - Kaizoku Hassyar - Fullbottle Buster - Steam Blade - Beat Closer - Twin Breaker - Muscle Glove - Solstall Wings - Giant Scratcher - Space Ride Arm - Spine Knuckle - Long Range Cleaner - Trash Converter - Gold Lio Gauntlet - Multi Deluge Gun
Pandora Box - Halfbodies - Fullbottle Holder - Build Phone
Vortex Finish - Hazard Level - Project Build - Sky Wall - Nebula Gas
nascita: Misora Isurugi - Soichi Isurugi - Sawa Takigawa - Kazumi Sawatari - Gentoku Himuro
Kamen Riders: Eiji Hino - Gentaro Kisaragi - Kouta Kazuraba - Takeru Tenkuji - Emu Hojo - Hiiro Kagami - Taiga Hanaya - Kiriya Kujo - Kuroto Dan - Parado - Sougo Tokiwa - Geiz Myokoin - Tsukuyomi
Prime Ministers: Taizan Himuro (Touto) - Yoshiko Tajimi (Hokuto) - Masakuni Mido (Seito)
Namba Heavy Industries Ltd.: Juzaburo Namba - Nariaki Utsumi - Haruhiko Wanibuchi - Guardian
Hell Bro's: Fu Washio - Rai Washio - Yoshikazu Takahashi - Norio Matsui
Aliens: Vernage
Gentoku Himuro - Evolto - Nariaki Utsumi - Takumi Katsuragi - Shingo Kuwata - Eita Kawai - Yoshikazu Takahashi - Norio Matsui
Touto: Needle Smash - Strong Smash - Burn Smash - Flying Smash - Mirage Smash - Square Smash - Press Smash - Ice Smash - Stretch Smash
Hokuto: Castle Hard Smash - Stag Hard Smash - Owl Hard Smash
Kaiser: Kaisei Mogami (World of Ex-Aid)
Kengo Ino - Ryoka Saiga - Mitsuomi Gobara - Evolto - Killbus
Keiji Uraga - Simon Marcus (Phantom Crusher)
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