TBF some of us have made theories in previous posts regarding the timeline - I even wrote about the events going in opposite order (2 before 1). Using the normal timeline, this is what I can get from both games.
1. Otherworlders have a hard time entering the human world, but they can poke in some places and exercise their influence in the land and its people, be it creating a curse on birth or providing visions to people with magic and power. Usually these are people whose faith is already wavering or those who see the Otherworlders as gods and saviors from an objectively hard and shitty life in fantasy Middle Ages.
2. Despite what I mentioned, neither the Observer (Sinisistar 1) nor the Father (Sinisistar 2) have shown skill for complex machinations or coordination of their followers. Their influence is not enough to abandon the Dream World, and they tend to be very passive besides cursing people and places. As a result, the great plans of these cultists may be using the power given by the Otherworlder they follow, but it may not align with its ultimate goal: the cult in Sinistar 1 sought to corrupt Rabiane into a sex slave and follower, and they believed that was enough; the priests in Sinisistar 2 go further and want her to give birth to the Father, but what they get is still not the real deal even if very close. As for demi-humans and the broodlings, they do their own thing, regardless of the ultimate goal of the being that enabled their birth into the human world.
3. What we know as Abomination Outbreaks combine experiments from cults of zealots devoted to an Otherworlder with cycles or cursed births that create the monster population raiding the countryside. As I mentioned in my other post, there is no big scheme to take over the lands and topple down big cities or kingdoms. Most of the time, an outbreak is akin to a plague that indiscriminately spreads in a particular location, and the cultists have shown a preference for remaining in the shadows while waiting for the right people to attempt their rituals.
4. Between the lack of demon armies and a dungeon/ demonic gate and the anonymity of the cults, the rulers of the afflicted land have little reason to care for isolated villages until the problem affects their taxes, their food, and eventually their own households. Requests for help may come from local churches and sisterhoods, or Sisters are sent to investigate suspicious supernatural activity.
5. Rabiane was sent to Kessaria with limited information about the problem but a clear plan: make her way to the Cathedral, which was believed to be the origin of the Abomination Outbreak. Why did she go alone? We find multiple Sisters petrified by the cultists in the Cathedral, so it is possible that Rabiane was part of that team but stayed behind (thus surviving). It is also possible she was sent later and found their map in the small church she stays in -possibly their local base of operations. Perhaps the Sisterhoods cannot afford to send more squads to Kessaria, and Rabiane had to take a solo mission knowing the risks.
Now here are two possibilities:
A. Despite the temptations by the Observer, Rabiane was successful in slaying it inside the Priest's Dream and stopping its influence in Kessaria. Assuming she survived the Pig Farm and the Lab, Rabiane returns to the HQ of her Sisterhood, and the years pass as new outbreaks happen in other places. Events of Sinisistar 2 would take place in another region, focused on Arcezon Town and its countryside.
B. Rabiane fails and gives birth to the monsters worshipped by the cultists following the Observer; whatever happened to Kessaria afterwards is unknown. Years later, there are rumors of an Abomination Outbreak in Arcezon, and the Sisterhood sends a pair of nuns in response, showing a change in strategy -fewer people, but better prepared in magical arts. The improvements on the arrows could be the result of the efforts in suppressing the Observer in Kessari, cleaning the land but losing many Sisters and their knowledge (the so called Saints).
