Brandon

Brandon is played by Ty Fuhrman. This page contains discussion of suicide. 

Season Four
Brandon is a member of Aurora Silver's cult. Throughout season four, he (along with Jonathan and another Unknown Voivce) spies on the Underhill through recording devices. After Jonathan loses a recording of The King's voice, Aurora Silver takes Brandon away for a task that is later revealed to be going to the Martin House and killing himself there. He shoots himself in the head after telling Mabel he's going into the ground for her. The bullet goes through his skull and then ricochets off of him, hitting Mabel in the arm. His body is eaten by the House and is later dropped in front of Anna and Mabel before being turned into a rattlesnake.

He's consistently referred to as "young man" or "kid" by the other characters, suggesting he's somewhere around 16-20 (confirmed in a post by Becca De La Rosa).