Dr. Jebediah Christoff was one of many scientists working under Director Phobos' command, working alongside Dr. Hofnarr and Dr. Crackpot. At some point in time, Christoff created the Sleepwalker Program, a project meant to help people better themselves by quickly reliving another person's life events, but his pacific approach did not go alongside the Director's plans, and required some time until proper approval.
Some time afterwards, Dr. Christoff and Dr. Crackpot had a feud, where they would attempt to redirect the Mining Sector's S-3LF extracting activities, sending emails to the MERC workforce where they would contradict each other and where Christoff would coin Crackpot's Enmeshment Program "Plan Zed". Despite the bickering, S-3LF extracting operations were resumed and Crackpot's Enmeshment Program was continued alongside Christoff's Sleepwalker Program, despite Crackpot's project having horrible results.
Dr. Christoff was plotting the fall of Phobos after learning of how the director weaponized the Sleepwalker Program instead of following the Nexus Charter handed by the Employers. Before taking action against the director, he warned The Sheriff about his plans in a series of emails and meetings with Dr. Hofnarr, and told him that he will need to become the leader of the residents of Nexus City when the Director falls, trusting that the mattress salesman was trustworthy of such responsibility.
Episode 1.5 is effectively the origin story of Jesus. Dr. Christoff used to be the chief scientist of Nevada's research fifteen years ago. He was in charge of a resurrective cloning project called Project Nexus, but something went horribly wrong with the experiments, and Dr. Christoff realized his research was being weaponized, so he defected from the project. He later enlisted the help of an old friend, the eccentric Dr. Hofnarr, whose high-level access granted Dr. Christoff entry into the Science Tower.
In the Science Tower, Dr. Christoff obtained his halo, an artifact which gave him the power to levitate, fire Nexus bolts that disintegrate weaker opponents and to drop projectiles that deal area damage around Dr. Christoff. In the Solarium, Dr. Christoff fought and killed Phobos, saying his catchphrase, "Good night, Phobos." Despite his victory over the Nexus, the narration stated that "The Savior's job is far from over."
Looking no worse for wear thirty years later, Dr. Christoff is a playable character in MADNESS: Project Nexus.
He plays a lot differently from other characters. Dr. Christoff's dodge is replaced by flying a long distance away, his charge attack is replaced by charging up his dissonance power to unleash a powerful AoE attack, and he can also pick up weapons and items from afar. He fires NEXUS bolts instead of throwing grenades, which seek targets and can dematerialize opponents if the bolt kills them.
After Hank sweeps through Dr. Hofnarr's office and doesn't find anything, Dr. Christoff floats down from an elevated platform above, after which he tells Hank that he won't find anything that will help him here, and then they fight.
After Hank defeats him, Christoff warns him that he won't gain anything from Project Nexus, to which Hank responds by saying that he doesn't want to gain anything from it, he's here to end the Project once and for all. Dr. Christoff then agrees to team up with Hank, and leads him to where Dr. Hofnarr is hiding.
Dr. Christoff and Hank make their way to the Sleeper Labs, finding out that the Sleepwalkers and other experiments within had been set loose and finally encountering Dr. Hofnarr (Now known as Tricky). The duo tries to convince Tricky to help them with shutting down the Divergence Engine, but initially Tricky refuses, and instead he forces them to fight for their lives in a dangerous room full of traps, being antagonized by the asylum's patients, orderlies and Tricky's special honk zeds which fall into the arena.
Mid-way through the killing game, some Nexus Core drones descend into the arena, annoying Tricky and adding to the hazards within the arena. Christoff and Hank survive the onslaught, and Tricky isn't pleased with it, so he activates a laser wall which slowly advances towards Hank and Christoff who have nowhere to run. Tricky talks and taunts the duo, but just before the laser wall kills them, Nexus Core goons break into the facility, so Tricky, Hank and Christoff team up to defeat all the Nexus troops present, and Tricky tells them where to find the Divergence Engine Keys required to operate the Divergence Engine.
After Tricky leads them to the Nexus facility with the divergence keys, he leaves them, and Hank and Dr. Christoff continue inside the facility. After making their way through lots of Nexus goons, Unfinished Mags and other experiments, they finally reach the room with the two Divergence Keys. Christoff uses his powers to store the keys in some sort of a pocket dimension. With each key they take, an Unfinished Mag comes out of it's chamber.
Just as they're about to get out, a third chamber opens, revealing Project Gestalt. Hank thinks he can take him, however Christoff warns him about Gestalt's power, and they decide to run away instead. Moments before they go down the elevator to the Mining Sector, Project Gestalt catches up to them, stopping Christoff and Hank from escaping. They fight Project Gestalt and he falls to the Mining Sector (killing Dr. Crackpot after his fight with Sanford and Deimos in the stage Chasms) after almost being crushed by the elevator's hydraulic press and falling down because the elevator collapsed from his weight.
While Hank, Deimos and Sanford enter the Science Tower, Dr. Christoff scouts ahead for possible obstacles on their way to the top.
Dr. Christoff and Deimos are tasked with activating the bridge, so Hank and Sanford can progress up the tower and disable it's defense systems. On their way there, they encounter Project Gestalt again and are forced to run, until Gestalt starts running too fast and falls out of a big window.
Christoff and Deimos activate the bridge, and then try to regroup with Hank and Sanford on a higher floor, however they're stopped by the Hive and forced to fight it.
Dr. Christoff wears a white scientist labcoat with belts and a bandaged-up body. On his head, he has the iconic Nexus Artifact, also known as the Halo. On his face he has a pair of sunglasses. His skin is also darker than that of a normal grunt.
- It is mentioned through Tricky's dialogue in Sleeper Labs that he and Christoff had teamed up to take on Hank at an unespecified place in time. It is unknown whether this is just a reference to the series, an event after Christoff's assasination of Phobos or an event during his time as a scientist.
- The "Stalker.mp4" short teaser seems to imply Hank (whose Hand is seen stabbing a photo with Dr. Christoff in it) was hired by an unknown employer to take care of him.
- Under Dr. Christoff's glasses, there's 2 black, empty eyeholes, similar to the ones in Madness Combat 8, except without the red spots in them. They are only visible to the player via modding the game or selecting the "Christoff" skin while using the mirror in the loft after completing Contract 3 of Arena Mode.
- In the 3D M:PN teaser "On The Wall.mp4", red, glowing eyes can be seen behind Jebediah's glasses.