|Season:||Kamen Rider Spade Warrior|
|First Appearance:||Episode 25|
|Last Appearance:||Episode 25|
|Number of Episode Appearances:||1|
Trial B is an Electric-Type Undead disguised as Rosalind's father, Zachary Sidney. Originally, his program was to protect Rosalind by her father because he was dying. Before he died, he transferred all his memories to the Trial. He is reprogrammed by Hadrian Kingston to continue to monitor the fixed Undead battle & remove potential threats. He dies saving Rosalind from Trial G after remembering his original programming.
- Trial B - Kamen Rider Blade counterpart at Kamen Rider Wiki