After the disappearance of Lucifer, Sierra is in Crowley's former lair with several other demons as they argue about what to do. Suddenly, the Prince of Hell Asmodeus arrives and announces that he is in charge until Lucifer returns. Asmodeus calls forward Drexel, Harrington and Sierra before smiting the rest of the demons in the room. Sierra later watches as Asmodeus explains to Drexel about his attempt to release the Shedim.
While Asmodeus takes Jack to release the Shedim, he leaves Harrington and Sierra to kill the Winchesters and Donatello Redfield. As Dean goes to grab his things from his room, Sierra ambushes him from behind with a knife. Sensing Sierra behind him, Dean dodges Sierra's first strike and fights back. Though Dean briefly pins Sierra down, Sierra effortlessly breaks his hold and slams Dean around the room despite Dean's best efforts. Advancing on Dean with his knife, Sierra is stabbed through the heart from behind by Sam with an angel blade, killing Sierra.
Powers and Abilities
Sierra appeared to be a regular low-level demon with all the powers of one.
- Demonic Possession - As a demon, he needed a vessel to walk the Earth.
- Immortality - As a demon, he would never age or die unless killed.
- Invulnerability - As a demon he was invulnerable to normal methods of harm.
- Super Strength - As a demon, he was stronger than humans and most monsters. In a fight with hunter Dean Winchester, Sierra was able to effortlessly throw Dean around the room and break his hold when Dean pins him to a table.
As a regular low-level demon, he possessed all the weaknesses of one.
- Higher Demons - He was subservient to and weaker than higher ranking demons such as the Prince of Hell Asmodeus.
- Angel Blades - Sam was able to kill Sierra with an angel blade.