Herbert Rock aka Flagstone was a member of the Myst, who had the ability to transform his body into cement, and also had the ability to shoot liquid, quick-drying cement from his hands.
After he was tasked with seeking out Harry Houdini, he was shot and killed during a fight in the speakeasy of The Grand Canary Hotel by Chanti.
He was described as looking like Bigby from Wolf Among Us.
Capers Abilities
Goo Generation (Major Power)
You secrete viscous, sticky goo from your hands.
Activation: Free Action
Target: Self
Range: NA
Duration: Continuous once activated
Effect: You create sticky goo that covers your hands. You cannot be disarmed. You can climb vertical surfaces at your normal Speed without making Trait Checks.