N36 a.k.a. David

Going by the fake name "David", N36 is the right-hand man of Falzar Sonavella and often whispers evil into his "boss'" ear. He often uses magic to disguise himself as a tiefling, hiding his appearance as a NITEN unit. But even his mechanical body is not his true form; N36 is truly a chain devil that has possessed a warforged he killed. N36 originally came to Nexus during the ancient war as a member of Moloch's army that used the world as a staging ground. Like his many compatriots, he became trapped on Nexus when the local mortals created a barrier separating the world from the Outer Planes.
He killed many people during the conflict, including one of the NITEN units created to fight the devil army. Seeing potential in the corpse, he possessed the body and began hunting down other NITEN units. He stole the parts from them that he found useful, augmenting his possessed body with pieces from over a dozen NITEN units over the years. Always on the hunt for more parts, he was rather pleased when he spotted N64 wandering around a swap meet. He also met Althea Filanes during this time, recognizing her sword as solacesteel and commenting as such when she let him examine it. N36 inquired where she got the sword, claiming he was disappointed she didn't get it somewhere he could buy one for himself. Truly, he was happy to learn the sword that was a devil's bane was beyond her means to replicate.
At an auction the next day, he bid against N64 for a docent from the great war. Much to his frustration, N64 outbid him as he thought no one else would be willing to pay so much for the item and brought insufficient funds to win the bidding. As he was leaving the auction, he approached N64 and asked if they could come to some sort of arrangement so it could change hands. N64 bluntly refused and N36 commented his behavior wasn't surprising since he was "just a kid", openly recognizing N64 as a NITEN unit in the process. He left the auction shortly thereafter, unaware that Vinnie overheard him discussing a lost treasure ship with Falzar as they departed.
Shortly afterward, Vinnie magically contacted N36 and claimed that the Argus Pirates were after one of the items Falzar had won at the auction. Realizing Vinnie didn't remember him from the war, N36 played along and said he'd reward Vinnie if the claim was true.
When the Argus Pirates attacked the kuo-toa village, N36 took advantage of their absence to board the Jeweled Eye and take control of the spelljammer, destroying their Abyssal Shard in the process. He used the ship's teleportation beam to retrieve N64's corpse and contacted the remaining Venture Boys, revealing himself to be a warforged. He openly stated his intention to harvest N64's body for parts, showing he'd done the same to many other NITEN units already (including N28) and dared the group to chase him into the Astral Plane.