Faylinn: the Leprechaun Kingdom
by Lost WoodrakePC1 mentions Faylinn briefly: it is more of a guild than a Kingdom, located outside Brun, maybe in the Isle of Dawn. Fanon often places it in the Redstone region. There is also full NPC info on the king, Iubadan, and a passing mention of his queen, Bero, his strongest knight Glower (who once cut a thistle with a single blow), and his chief bard, Eisert. That's what we have from canon, AFAIK.
I suggest locating Faylinn castle in the woods south of Crosston at the Isle of Dawn. It is invisible to mortals, and located at the center of a small lake, Loch Falleagh. At times, two rainbows emerge from the castle - Iubadan's and Bero's. Each is a bridge leading to a pocket plane, where the royal couple keeps their separate treasures (their fabled "pots of gold").
The kingdom of Faylinn oversees several guilds of leprechauns. The major ones are shoemakers (the largest and most influential), tailors, weaponsmiths, and creators of magic items. A unique guild, composed by an entire sub-race, is the clurachauns (see PC1, p. 30), who inhabit wine-cellars and take care of caskets, beer barrels and the such. Compared to the industrious leprechauns, clurachsuns are more chaotic, and tend to get drunk and rowdy.
NPCs:
- Iubadan: as detailed in PC1, p. 56
- Bero: the queen of Faylinn is often in charge when Iubadan is off on his travels. She is sharp-minded, sensible, and has a great mind for numbers and finances. While Iubadan is more adventurous in spirit, Bero finds real joy in actually managing the industrial and mercantile aspects of Faylinn.
- Glower: besides the remarkable thistle feat, little is required of the king's knight in terms of defense in the tranquil Faylinn. He often accompanies Iubadan in his travels, and the duo at times sneak away for some mischief.
- Eisert: the chief-bard earned his fame for writing a long epic poem about the thistle incident.
- Nundar: head of the guild of magic creation, and inventor of the famed Shoes of White Bronze (PC1, p. 60). Tends to be secretive about his craft, but can be lured into enthusiastically divulging inforamtion.
- Olta: head of the clurachaun guild. Robust, cheerful and red-cheeked, she skillfully manages her guild from the cellar of "The Weary Wyvern", a successful tavern in Donahue's Cove.
- Fitznaharan ("Fitz") O'Danahan: ambassador of King Oberon's court. A pooka who prefers to appear as a fox wearing fashionable Thyatian clothes, and spends most of his time messing with the minds of Thyatians around Redstone. He doesn't really have much to do at Iubadan's court. However, following the Fall of the Canolbarth, Fitz's time-manipulating powers proved essential in enabling the court in the Dreamlands to be evacuated to Redstone with minimal harm.
- Luhnn ap-Dwydd: ambassador of Annwn. A pale, solemn and quiet sidhe, he is a stark contrast to the boisterous court. Resides in a cave under the woods. Relations with Annwn are cordial but not without suspicion, and it is unclear whether Luhnn should be treated as a diplomat or a spy.
- Vev Foamrider: ambassador of the Minrothad Guilds, who is mainly in charge of trade relations. A water elf belonging to Guild Corser, she was sent years ago by Master Magic Dealer to the Isle of Dawn in order to find fey magic items, and stayed since. She tries to retrieve more information from Nundar about rare magical items, in what is by now a constant chase that greatly amuses the Faylinn court. Resides in Crosston.
- Mikaela Al-Azrad: ambassador of Darokin. Born to the Hallonica House, she married Rasheem Al-Azrad from Selenica and joined him to a trade mission to the Isle of Dawn. For some reason, the leprechauns chose to enable her to find Faylinn, and unbeknownst to her husband (who cannot see the leprechauns), she manages trade relations for the Republic since then. Resides in Crosston.
- Velospanius Aristaphes: Thyatian emissary. The leprechauns tend to view the empires' rivalry in the Isle with detached amusement, and have little respect to Thyatians. Yet since the human mortals do rule over Redstone, business with them cannot be avoided. Velospanius grew up in Foreston, which makes him more acquainted with woodland folk than other Thyatians, and therefore slightly less obnoxious in the leprechauns' eyes. Still, he is relatively new in the Isle and yet has to prove himself. Resides in Newkirk.
Higher Faylinn
Following the notion set by Havard that Fey kingdoms in Mystara, such as the Dreamlands and Annwn, have a correspondent in another Plane (the Feywood/Feydark; Alfheim/Svartalfheim), I would suggest Faylinn as a legendary Plane (as part of the Feywood or with a gate to the Feywood?) full of gold and treasures, some of which might prove illusionary for mortals. That being said, I really understand very little about the Planes, so I would leave that work to others...