Aethera is a science fantasy setting for Pathfinder; Starfinder is a science fantasy setting and system descended from Pathfinder. There was stretch where Aethera might have been adapted to Starfinder’s rules, when the system was announced, before they decided to keep going with Pathfinder. Today, I’m going to speculate on how the two might overlap, for those so interested.
So the core underlying thing with Aethera is that, somehow, the entire system has been severed from contact with the Astral Plane, and from there the Outer Planes. They also have history that goes back around 4000 years, and a plane where time is fractured, badly, with some portions still caught in the events that broke that planar connection.
Starfinder, meanwhile, has a temporal gap of around 1000 years, give or take, and the world of Golarion has gone missing in the absent timeframe. You could easily draw a line between these two events – the Evermorn of Aethera might well be the theoretical plane of time in the rest of the multiverse, and the events in Aethera that broke it could well be the catalyst for the Gap. If time broke locally, and the broke section jammed the entire plane, it’s reasonable to think that this might have a backlash across the rest of the cosmos. The gods either not knowing or refusing to talk about the events of the Gap to their followers could also draw a line to it originating somewhere they can’t reach.
Conversely, the inhabitants of the Aethera system would have no idea about the Signal – the divine nature of it means that they’re outside the reach of the Triune and they’re stuck working with aethership systems. The Drift might not even be accessible from inside the system, depending on exactly how the planes broke. The first clue a starship with a Drift drive would have that something’s up is when they find a shredded portion of the Drift that they can’t pass through, and drop out to find themselves on the remote edge of the system.
Picture that – the only actual starship in a system, capable of crossing interplanetary distances at a reasonable clip without using the Gate Hubs, confronted with planets that are so blatantly tied to the elemental planes, with bizarre spacefaring ships that look like nothing even remotely familiar – and there’s no ‘ping’ from the Astral or the Drift there. The ship would be just as much of a game-changer for the Aethera system as the arrival of the taur and their theft of a moon.
The taur, in turn, use ships that transit more rapidly via Shadow; given that Paizo has mentioned a previous stardrive that used the plane of shadow for increased speed, it’s not hard to think they might use it. If the arriving ship can capture a shadow drive from the taur, or have plans for one in their computer system, they can revolutionize the Aethera system’s internal travel and make fighting the taur a real possibility.
More than that, though, the classes of Starfinder don’t rub raw against the Aethera setting; mystics, the only ones who you’d expect to be inconvenienced by the Astral break, can likely learn about the Score and draw their power from it, letting them function without breaking the setting or the rules.
And, from the standpoint of Starfinder, Aethera provides a wealth of possibilities – access to the Evermorn, which might be the plane of time; access to aetherite itself, which they might be able to synthesize from Astral energies once they leave the system; and possibly a way to seek out the cracks of flaws left behind by the Gap, letting them piece together what happened and maybe even get a hint about the lost world of Golarion. It’s all very, very tempting – and it goes the other way, too.
Because what happens if an aethercraft ends up transited into the Drift by a malfunctioning Gate Hub, and ends up having to make a deal with spacefarers from the wider cosmos to even get out, now lost? Their aethercraft is utterly unique technology, and if they can discover a way to create more aetherite they might end up with a hybrid craft in their search to return home – and bring the wonders of the wider cosmos with them. How long before word of Aethera spreads and the descendants of the Rahadoumi make their way there to be free of the gods for real? How long before Pharasma realizes an entire star system’s souls aren’t passing into the River of Souls, and sends mortal agents to gather information and seek a way to fix the problem?
How long before Baphomet finds a way to reconnect with his lost worshippers, the taur, and brings them to bear on properly conquering the system?
And how long before some other menace – the Swarm, perhaps – descends on the system, unsuspecting, with a race against time as the lost Aetherans rush to get home and prepare their people?