This is a listing of some seeds from which you could build situations for tabletop play. Each also notes in italics what situation-builder is most likely to give you helpful guidance in fleshing it out, though this guidance may only be loose in some cases.
Trouble In The Valley
Long Knives
A localised (in the same valley, typically) group of villages, some of which follow old ways and some new, are having rising tensions. At least one king of a Milia village thinks (and have always thought) that the champions of the Saesin villages are no better than cattle thieves, and that their elders are sad and ineffectual. In return, some Saesin champions feel that the Milia warriors are "Like rats swarming to fight a lion", and many elders feel that the Milia are despoilers of nature. Additionally, there may well be feuds between Saesin champions, and potentially a coven of witches with their own strong opinions. Things start to spiral towards violence.
Young Master
Broken Places
A single dun (hill fort), which may include or overlook a village, has been taken over by forceful occupation or resource seizure. The mastermind behind this seizure is almost certainly someone who has beliefs in line with those of Balach, though they may well deny this (even to themself).
The Shrine Cult
Broken Places
A local spirit of place has awakened and declared itself to be the god of a region. It has significant magical power within a specific domain (beasts, earth, air, etc), and it shares this with followers that actively work to build its power. If using Witchcraft for Schema, this might be a hearth that has subverted or slain its coven.
What The Grey Wants
The Quest
A powerful luminary - a high king, the grey witch, a semi-mythical figure, has called for the characters to attend a specific place (often, where the luminary is), and pick up some person, artifact, or other necessity. This is then to be taken to another location and used there to create some gain or prevent some great danger.
Death Walks
Predator
All the shades of an ancient mass grave have risen up and taken control of an unwise witch that sought to send them to rest. This witch has been transformed by their magic into an undying pale wanderer, who seeks out victims that can be likewise transformed so that the shades can divide themselves out - eventually, aiming to hold a single transformed body each.
Cold Iron
Futurity
A blacksmith serving a very strong king has discovered that iron mined from a specific cliff face siphons up magic that it touches. Naturally, the moment this becomes known, the discovery is seized on for expansion.
Called To Rule
The Estate
A Saesin circle of elders can traditionally name anyone their champion, though they normally select one by warrior trials. Likewise, a Milia throne-gathering can name anyone the king or queen, though this is more typically a direct democratic selection. However, typical is not always; a village with difficulties or an odd process has called an unexpected choice... Such as a player character residing near enough for their reputation to have reached them.
Second Of That Name
Transgression? Futurity? Dealer's choice.
A dying king has declared it law that his daughter will be queen after his death - that there will no selection process or trials at all, as is the normal case among the Milia. He has sworn all the warriors of his kingdom to enforce this. His daughter, in turn, has declared that once she is queen, she will create similar laws of inheritance for other positions. The kingdom is unsettled as a result, with some expecting riotous violence; however, the situation is unprecedented, and many other kingdoms are looking to it to see what will come of this.
The Bent Gate
The Devils We Know
A coven of witches whose steading includes a permanent gate to some of the worst parts of Faerie are sworn to keep it closed and its existence entirely secret. Their rites for maintaining the seal, require that a child stand before the gate in vigil for a night once each year; this process has been killing these children for the last few years, and the oath of secrecy means that the coven cannot explain the matter; they have taken to kidnapping children. The coven itself is slowly becoming distant and cruel, partly by attrition; several of their members have committed suicide rather than break their oath or keep it. The characters are given a reason to investigate.
Into Faerie Lands
The Expedition
Practically everything in Faerie has been enhanced and improved on with magic, including the crops and livestock. Should a gate into Faerie be opened that leads to a place that is relatively isolated and safe within Faerie, expeditions could be mounted into it to raid a little livestock, cut a few plants, lift the tools from a forge, and so on. Of course, getting to the gate (which might be deep in the wilder parts of the wood, at the edge of a waterfall, or somewhere else troublesome), getting from the gate to an occupied area, getting in and out with what you want, and making it back home with possible pursuit might be quite the piece of work.
Hive-Hearths And Balach-Barrows
Dungeons
Some spirits of place turn hostile to humanity, and build themselves defences and guardians to ward people away. Some such spirits were even 'turned' by Balach in the invasion - and of these, ones hidden away in the earth and slumbering undetected in ruins other means are the most likely to still exist. These places are terrible perils to any who come near them, but raiding them for the wonders and spoils within, or going to war against them outright, is sometimes desirable or necessary.