The Strong Smash was created by Faust from a man named Shimizu and sent after Ryuga Banjou after he escaped from being experimented on by them.
It came upon Ryuga as he was with Sento Kiryu and attacked them both. In response, Sento transformed into Kamen Rider Build and fought it off. After defeating the Smash with Vortech Finish, Build extracted its Smash essence with an empty Fullbottle, reverting Shimizu back to his normal self.
Strong Smash Hazard
Faust later abducted Kyoka Katsuragi, the mother of Takumi Katsuragi, and turned her into a Strong Smash Hazard. She was soon defeated by Kamen Rider Build and reverted back to her original self.
Later on, a Touto soldier was turned into a Strong Smash Hazard by Night Rogue. He was defeated and returned to normal by Kamen Rider Cross-Z.
Strong Clone Smash