The Smash are monsters engineered by the Faust organization and antagonists in Kamen Rider Build.
They are created when a human is injected with Nebula Gas, triggering a rapid cell division and causing them to lose their sense of consciousness, turning them into a rampaging monster. In order for a Smash to be reverted back to a human, it must be defeated and have its Nebula Gas absorbed into an empty Fullbottle.
Later on, during Faust's alliance with Hokuto, a new type of Smash was created called the "Hard Smash", which would possess the superhuman abilities of a Smash while also retaining its human consciousness. The Hokuto Three Crows were each turned into a Hard Smash, becoming elite soldiers of Hokuto under the command of Kamen Rider Grease.
Eventually, Faust developed the final form of Smash, "Lost Smash", created by infusing an empty Fullbottle with the essence of a Clone Smash. To engineer Lost Smash, Evol ambushed Kamen Rider Grease and stole the Fullbottles of the Hokuto Three Crows, planning to use the Lost Smash to destroy the world.
- Needle Smash
- Strong Smash
- Burn Smash
- Flying Smash
- Mirage Smash
- Square Smash
- Press Smash
- Ice Smash
- Stretch Smash
- Fang Smash
- Castle Hard Smash / Castle Hard Smash Hazard
- Stag Hard Smash / Stag Hard Smash Hazard
- Owl Hard Smash / Owl Hard Smash Hazard
Hard Smash Hazard