Dusken Glade Rivals
In Xanathar's Guide to Everything, the Downtime Actions section introduces the mechanic of Rivals: NPCs who aren't necessarily villainous - and in fact, some of them may be actively good - but who dislike the player characters for some reason and work to stymie or get in their way sometimes.
The Elven Courtier
To those who do any kind of business at highest levels, or who engage with noble society, Davil Starsong is a familiar sight. Quite simply, Davil is a wheeler-and-dealer in Waterdeep, putting his sun elven charms to his best personal use. He seems to know everyone and to be everywhere. He is a hard partier, and only too happy to use his bardic magic to get his way (all within the bounds of the law, of course). He is a dealer in favors and connections, a fixer who seems to know everyone and how to get things done.
Rival To: Lola, Orion, Psalm
Agent of the Waterdeep Watch
The half-orc Luchezga is a pugilist and fighter of some talent. For many years, she was part of the cage-fighting circuit, and beat a good many folk in the ring with her unarmed fighting tactics. Eventually, though, it happened: the Watch raided one of the biggest Griffin Gathers during a big fight, and she was instrumental in seizing and arresting Valesta. As it turned out, Luchezga is a member of the Watch, and she'd been planted among the fight scene in order to identify and arrest the people involved. Luchezga escaped her apprehension on the way to gaol, though, which is a source of great frustration for the fighty half-orc. To this day, she still seeks to dismantle the gangs of Waterdeep. She is a student at the Monastery of the Sun, studying the Way of the Sun Soul with Abbot Alger.
Rival To: Clarc
The Freelance Gangster
It is the rare crook who can walk the razor's edge between the Xanathar's Thieves Guild, the gangs, and all the other criminal enterprises, and not get cut. The drow Torthar, called Bloodcloak for his signature dark red mantle, is one such criminal. Nearly an urban legend in Waterdeep, Torthar has dealings with most of the major criminal enterprises in Waterdeep's shadows. He is dangerous to betray, and those who come hunting him frequently simply disappear entirely. He does mix and mingle with the surface-dwelling drow of Waterdeep, albeit the leaders of those drow are hesitant at his presence: he is one of Vhaeraun's Called, and considered something of a bad influence, often drawing newly-arrived drow into criminal undertakings meant to gain them the coin they need to survive in a place where finding regular work can be incredibly difficult.
Rival To: Psalm
The dwarven wizardess was one of the first apprentices of the renowned but reclusive Ahmadar of the Seven Runes, one of the earliest known dwarven wizards in the wake of the Thunder Blessing of the dwarven peoples. Whorbi is not merely a member of the noble dwarven Clan Worldthorne, and thus one of the most important members of the dwarven community in Waterdeep. She is also a Harper of some rank, and takes the responsibilities and traditions of the Harpers very seriously.
Rival To: Orion, Clarc
A prominent wizard with the Watchful Order, Rangur Wands is a proud inheritor of his family's arcane legacy. He tends to distrust "the rabble" with the powers of arcane magic, finding them selfish, boorish, and insufficiently civic-minded to be trusted with the heights of the Art.
Rival To: Aka
Rival To: xx