If our beliefs produced gods, then do alien species have gods? This is a sort of Far Future Scion or American Gods kind of story, I suppose. It's about taking a not-uncommon premise from contemporary fantasy and melding it with science fiction.
So, let's do this.
The gods (by which we shall refer to any divinity at all) are repeatedly reincarnated. The timing and placement of said births depends on the strength and (geographical) concentration of faith focused on a given god. Gods do not know their nature at first but they may be awakened to it through a suitable trigger event that is based on that god (so St. Christopher would require a different trigger event than Krishna or Huehuecoyotl). A greater "push" is required to awaken a god that is not the focus of as much faith, and memories of past lives slowly soak into the god after an awakening until the god's current life is swallowed up in the gestalt of previous lives.
Some force or other effect is required for the awakening process. This force waxes and wanes around our world over time, but the aliens' world had no such situation. Their gods steadily progressed into a position of open rulership, whereas our pantheons would begin to be wiped out whenever awakenings ceased.
Eastern Asia is in a position to dominate the world because of the relative strength of its pantheons. There are a few angels and saints running around as well.
Ragnarok is a muddled recollection of events already past, which were later considered to be in the future, and most or all of the Norse divinities were killed in some manner which prevented reincarnation. Other gods have sometimes died in a similar manner but only rarely.
The aliens and their gods still work closely together and the invasion is heavily reliant on the powers of their gods. The aliens have taken advantage of the mechanics of godhood in some way. Earth's gods will need to rally their mortals in order to successfully defend against the invasion.
Do the aliens's gods want more worshipers? Is that why they are invading? Is this a sort of extraterrestrial "conversion by the sword" thing? Belief probably doesn't actually strengthen a god, at least after a god has awoken. Rather, it makes awakenings in general more common. Did the powers of the alien gods make FTL simple enough that they have the ability to travel from world to world but not to terraform, so they are looking for living space?
The pantheon of the aliens has become more or less unified over time. There are two sun gods and perhaps as many as three moon gods, mirroring the double suns and triple moons of the aliens' homeworld.
The powers of the gods are things that we would be able to label as "psychic." Not so much (or at all) on the bodily transformation end or anything like that, but there is telepathy, maybe probability-based precognition, remote viewing, telekinesis of various kinds, mental projection, mind control, maybe even something as far as bending space.
Some awakenings have happened already by the time of the invasion. For the story, maybe the invasion is already in progress. The aliens are fighting strangely because they are trying to take prisoners as often as possible. They are minimizing casualties all around, on their side and on ours. Assuming, of course, that they're trying to grab worshipers and suchlike.
But why not just clone new worshipers by the thousands, either of their own species or of ours after we have all been killed off? The answer is the same as it would be if they were looking for living space: they don't have the technology for it. They have sufficient numbers of gods who can bend space that they can go from one world to another, but they have not been operating for long enough to, for example, figure out effective cloning.
There is a reason that they are looking for worshipers besides raw power, though. Even as the population grows there are still more gods being created by the aliens as time goes on. At one point the various gods tried to kill each other permanently in order to clear the field but nobody does that anymore (at least for the actual purpose of reducing the number of gods around; it might still be done as a punishment or something). And so there are more and more gods with every generation, even as the overall population expands.
The aliens are not afraid of dying, you see. Those of them that are gods already will certainly be reborn, and those who are not yet gods will have tales spun of them that will inspire worship, if only they do a good job of serving the existing gods. But gods do not have faith, so as you have more gods there is less faith to go around, which makes it harder for awaken any particular god.
The solution is to get believers whose gods will not be of their species. You will stamp our their faith in their own gods and so, for generations without end, they will continue to fuel the awakenings and re-awakenings of your own people. It is the doctrine of the gods of these aliens that eventually all of their people will be made into gods, and only gods will be born to them, but for this to happen they need an empire of beings who are not their own species.
Just for funsies: gods taste different than non-gods, at least to gods. So ritual cannibalism is a Big Thing for the alien gods, and also you get some horrible scenes of alien gods eating some of our protagonists and whatever.
Which means that the aliens eat meat. They're predatory. They're like wolves and octopi and wasps blended together. Their wings are vestigial, for threat displays. They have extended mouths, like if elephants kept their mouths on their trunks. Also, multiple mouths, each on a different spider-octopus-like limb. Maybe the wings are capable of all sorts of fine communication, so that the aliens have a sign language based on wing movement. Maybe their "fingers" are pedipalp-like things that were first used to grab food and direct it to a nearby mouth but now have much more dexterity.
Questions to answer:
- How do you kill a god in such a way that it does not ever come back? That is, how did Ragnarok happen? Learning how to do this will probably be critical to winning the war.
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.