Archfey

An Archfey is a powerful fey creature with the influence, understanding, and power to bend the surrounding Feywild to its will. Most Archfey belong to the Seelie Court, the Unseelie Court, or one of the other courts, but may even be unaffiliated, like Artagan.

Known Archfey
Some of the Archfey of the Feywild are identified in the Material Plane, either by scholars or mortals making deals with them:
 * Lord Artagan of the Morncrown: A courtless Archfey. He was in the Arcana Pansophical records as of 812 PD
 * Lady Elmenore the Unforgiving: Matriarch of the Seelie Court. She was in the Arcana Pansophical records as of 812 PD
 * Keeper of the Moontides: A mysterious Archfey. A spy of the Arcana Pansophical went missing investigating about them
 * Potentate Sammanar: Master of the Unseelie Court. They were in the Arcana Pansophical records as of 812 PD
 * Lord Saundor the Forsaken: Master of the Shademurk and former wielder of Fenthras. He figures in the Arcana Pansophical records as "reportedly deceased"

In Explorer's Guide to Wildemount, Queen Titania is named as the Queen of the Summer Court. The guide does not directly describe her as an archfey, but in the Forgotten Realms, she is the archfey leader of the Seelie Court, which is also known as the Summer Court. She is additionally mentioned in an out-of-game comment by Matt in Campaign 1 as an example of a fey character from another work (here, A Midsummer Night's Dream) who would be an archfey.

Pre-Divergence
Before the Divergence, Artagan tricked a nascent civilization of elves into worshipping a whale carcass. This drew the ire of the elven god Corellon, who banished Artagan from the Material Plane.

Campaign 1: Vox Machina
When Syngorn was in the Feywild during the Chroma Crisis, Artagan helped some fey, including a pixie prince named Windybranch, to slip through the city's defenses, where they occupied a noblewoman's manor and transformed it into a fun slice of the Feywild; she tried to reclaim her home for years afterward.

Artagan played an important role in Vox Machina's adventures. He guided Vox Machina on their quest to slay his fellow Archfey Saundor (which yielded Saundor's mighty bow Fenthras for Vex'ahlia) and when they retreated to the Feywild, he ensured they could get a full rest and stop Vecna before the lich's miracle of terror was completed. As part of the deal for his aid, Vox Machina built Artagan a doorway back to the Material Plane.

In the meantime, several members of Vox Machina had taken a vacation to the Feywild. Against Artagan's advice to avoid the Theater, they snuck in to watch a performance of the Royal Troupe of the Unseelie Court; at the end they saw an "entity" step back into a doorway, signaling it was time to leave; this entity was presumably Sammanar.

Campaign 2: The Mighty Nein
Artagan used the doorway Vox Machina built for him, and thereby became the childhood friend and patron of Jester Lavorre. Through his ongoing and evolving relationship with her, he guided the Mighty Nein throughout their campaign. He had amassed hundreds of followers, but wished to unburden himself of almost all of them. With the help of the Mighty Nein he gathered them all on the island of Rumblecusp in an event known as Traveler Con and tried to trick them into believing he had always been Sehanine in disguise. This went awry when one of that goddess's powerful servants appeared and nearly re-banished him.

Exandria Unlimited
Lady Elmenore had some kind of possessive relationship with the faun Fearne Calloway, but Fearne's grandmother helped Fearne travel from the Feywild to the Material Plane. During her adventuring party's travels, Fearne was drawn into a confrontation with a dark, more powerful version of herself wearing the Circlet of Barbed Vision, and this dark alter ego said the Warqueen wanted Fearne back. After the battle that followed, Fearne could feel Elmenore's displeasure at the dark alter ego's failure.

Trivia

 * Unlike the rest of the fey, Archfey are immortal and immutable.