Stag Smash

The Stag Smash is a Smash monster engineered by Faust in conjunction with the Hokuto government and an antagonist in Kamen Rider Build.

Stag Hard Smash
The first Stag Smash was created from Aoba after he volunteered himself for Faust's experiments alongside Akaba and Kiba. They were thus all turned into Hard Smash, Smash who retained their human consciousness.

When Hokuto declared war on Touto, Aoba was sent in alongside Akaba and Kiba as part of the Hokuto Three Crows led by Kamen Rider Grease to spearhead the invasion. After being upgraded to a Smash Hazard, the Stag Hard Smash met its fate when it was killed by Build RabbitTank in his Hazard form during a brutal rampage.

Stag Lost Smash
A Lost Smash version of the Stag Smash was later created by Evolt infusing the Kuwagata Fullbottle with the essence of a Clone Smash. Given to a man named Kyouichi Shimizu, Evolt sent Shimizu out to transform into the Stag Lost Smash and defeat Kamen Rider Build. After being defeated and purified by Build Genius Form, Shimizu was killed by Evol Black Hole before he could reveal any incriminating information on his plans.