The Sergeant, formerly known as Sgt. Nef Anyo before Update 16.4 (2015-04-23), is the final boss of Phobos system. He is in charge of the Corpus Solar Rail systems, using them to obtain Cryopods with dormant Warframes for resale to rogue scientists and splinter groups. When confronted by the player during the mission, he has a very aggressive tone towards the Tenno and warns the player that they are making a fatal mistake by attempting his assassination. He also may demand information regarding Orokin secrets, or make fun of the player's Warframe or teammates.
The Sergeant resembles a Sniper Crewman, though with some aesthetic differences, such as being slightly larger and having a black suit instead of a yellow one, a red visor, and red markings on his helmet.
- : A charged sniper rifle that deals high damage.
- Flash Bang: Throws a flash bang onto the ground, rendering himself invisible. Despite this, the objective marker will give away his position when he becomes visible again.
The Sergeant is essentially a stronger Sniper Crewman with a tendency to exploit hide-and-snipe tactics as opposed to the head-on-assault of most bosses.
Aside from depleting his shields and health, there is little in the way of strategy to the overall battle. As the Sergeant is always vulnerable to damage, the Tenno only need to attack him until he is defeated.
- Supposedly, Nef Anyo will be the next boss to be revamped. However, this was "confirmed" before Nef Anyo was renamed to The Sergeant. Concept art depicted The Sergeant floating on a platform while being accompanied by his Nephew Derf Anyo. It is unknown if Derf is the nephew of The Sergeant or the Nef Anyo revealed in Operation: False Profit.
- It is likely that The Sergeant is just a placeholder until the complete revamp of Nef Anyo is ready to be implemented, most likely in the aftermath of Operation: False Profit.
- The Sergeant is in charge of the Corpus solar rail systems and has been using them to obtain Cryopods with dormant Warframes for resale to rogue scientists and splinter groups. He was targeted for assassination so that the Cryopods can be rescued.
- Despite being the second Corpus boss after the Jackal, due to his vulnerability to shock damage, low shields, and low health, he is the weakest boss in the game.
- At first, Nef Anyo had a red visor, but it was changed to a blue one like regular crewmen at some point. So far, his visor has gone from red to blue to red and back to blue again over the updates. His visor is now red again for the time being, along with red markings on the helmet.
- Prior to Hotfix 7.7.3 (2013-04-12), there was a glitch where when The Sergeant cloaked himself, he never uncloaked again, making it difficult to fight him without an Enemy Radar.
- As of Update: The Silver Grove (2016-08-19), The Sergeant is the only boss who does not have an opening cinematic.
- So far the only non-robotic Corpus bosses are The Sergeant and Alad V.
- As of Update 13.0 (2014-04-09), he has received a new look with red patterns on his helmet and can speak with the normal Corpus Crewman's language.
- His visual transmissions contain little animation, and simply portray his static 3D model in the idle stance commonly used by Corpus humanoids. This is likely because crewmen have no speaking animation.
- Similar to Tyl Regor and Ambulas, The Sergeant does not drop any rare mods.
- The Sergeant has two entries for in the Codex drop table.
- Sometimes, with high latency issues, you are able to disarm The Sergeant, however, he will still act as if he had his Lanka as he holds the stun baton like his rifle.
- Interestingly, when The Sergeant appears as the main focus of a Sortie, he will be referred to as "Nef Anyo" in the description.