"Your mind is a wasted thing. I will correct it."

The Mind Flayer Nihiloor works for Xanathar, the paranoid Beholder crime lord of Waterdeep. Spending its days creating an army of Intellect Devourers, it then sets them loose in the sewers of Waterdeep. With each victim they attack and take over, Nihiloor grows his network of thralls to manage a spy network that covers nearly half the city. With the information relayed back to the powerful mind flayer, he then directs the Xanathar forces as needed while pursuing his own twisted goals.

None are safe from the Mind Flayer's objectives, with agents already in the City Guard and City Watch, many Waterdavians have fallen victim to his machinations. Sending orders such as the capture of specific Waterdavians, Nihiloor brings them to Skullport where they can be enslaved or ransomed. The reason is the mind flayer seeks to dominate the population little by little, in truth a liaison to the Ulitharid Extremiton deep within Undermountain. Farming the city for its residents, Nihiloor acts as the Ulitharid's eyes, ears, and voice in dealing with the city's population while it grows its objectives under the city. Nihiloor uses Xanathar as a false crown, working humbly under the crime lord while its true master crafts the Alterdeep, a simulated Waterdeep that allows the Mind Flayers to have experiences of the city through the thoughts of its population. Willing or otherwise.

When the Zhentarim and Xanathar went to war in the city of its already escalating financial crisis, Nihiloor took the opportunity to start to expand further the illithid colony under Extremiton by instilling more Intellect Devourers in its population. However, the recent Githyanki warring against Extremiton in the Undermountain has left the mind flayer with a sense of isolation. Unable to rejoin its colony and share the experiences it helped deliver them, Nihiloor now plays a careful game of survival to save itself from the many factions that are taking advantage of the chaos. Despite the persistent mental connection to Extremiton, Nihiloor is aware that if it is killed, much of the mind flayer colony's food source will be difficult to acquire. Sharing the Ulitharid's desire to farm the population and not rule it, Nihiloor will bargain its loyalty against all those in the city if it can continue its existence serving the grand design of its hidden illithid colony.

Personality

"I do not desire to rule the Xanathar, however it may seem. My goals are much more reachable than that."

An oddity of an illithid, Nihiloor flatters, lies, and manipulates its victims to set them at ease before it strikes with uncaring precision. Finding all in the city beneath its intellect, Nihiloor believes that much of the population would serve well under its colony's influence with the city's struggles seen as repetitive. Having secured the position in the Xanathar through manipulation, it finds the city vexing for how it trudges on despite the wonder of some of the lifeforms that walk its streets. The many intellect devourers under its command provide it a library of sources to learn and monitor, enhancing its already curious nature into why the beings act the way they do. A trait Extremiton found valuable, and is why it placed Nihiloor in charge of kidnapping the Waterdavians for the colony below.

With its own fill of brains from the population, Nihiloor has learned how to read emotions well to get whatever they desire in a moment's need. Knowing guile and submission can get one farther in the city than strongarming, Nihiloor uses flattery while in the presence of the Xanathar to act weak being valuable for his mind rather than body. This is a lie constructed by the mind flayer, revealing its true self in the presence of adventurers or those it knows are more intellectual than the grunts it surrounds itself in. Among those worth its time, Nihiloor is honest in its disdain for the Xanathar itself alongside their activities in the city. It views them as the most useful pawns in its role to achieve Extremiton's demands, knowing any alliance with others be fleeting due to its illithid nature.

Despite its role as a spymaster for the Xanathar, Nihiloor views Xanathar as a scapegoat necessary for it to maintain its cover in the criminal empire. With the aberration as head of the criminal group, it is the target of strife in and out of the gang allowing Nihiloor to operate without concern due to its species reputation. Though the alien creature wouldn't admit it, Xanathar's control of the large faction does impress it despite the beholder's rampant paranoia. The history of beholders that have ruled the criminal organization in the City of Splendor has given the mind flayer some loyalty for its uses, though its loyalty will always be with its colony hidden deeper in Undermountain. Nihiloor would not supplant the beholder unless Extremiton deemed it necessary, an awareness that Nihiloor would shoot down any who suggest it should rule as head of Xanathar with apparent dismissal.