As I've seen this game ordinarily played, there are few and far between multi-dimensional threats. This works fine, but some people are going to expect recurring villains that have more of a back history than 'the verser created them in one universe'.
You could play a Multiverser campaign that was more about some pan-dimensional enemy than about each individual world. This is similar to how in Champions you're a super hero, but they also made the setting books to deal with being a street-level vigilante. The first really enfolded the second, but the second has such appeal that they made books specifically for it.
We've dealt with various forms of dopplegangers, and I've sketched a world of 'illegal aliens' from alternate realities. And it would be good sometime to go back to the idea of a pan-dimensional devouring force spreading across alternate realities like a plague (the Dark Interdimensional Empire) and (The Pan-dimensional Vampire Plague that destroys all life on a planet and then moves on.) Thats not for now.
Projectives
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On Earth Real, the oligarchs of the New Understanding were benevolent, kindly, guiding souls. If you doubted this, just ask them yourself.
The various nations of the ER, or Earth as it had been known in the darkened days Before, still clung to the old ways, and the Old Gods. The Gods were a pantheon known for their strict moral code, and their inventive punishments for those who broke the code. But the Gods had not been seen on Earth for centuries, perhaps millenia, perhaps suggested some of the more radical thinkers, never. Or perhaps the Gods had died. In any case, with the rise of industrialism, and the factories, the old myths were dust or so said the Bright Young Things.
With a bit of drug, and a bit of meditating, and some bits of philosophy gathered from here and there in an eccletic mash, the New Understanding grew. And these, the children of the elite, the few who suffered for their refined understandings and sensitive ways discovered doors in their minds. A certain union of thought and idea, the Freethinker's Guild, gave way to genuine pschyic power.
Techniques were developed, and these techniques were so laden with meaning and symbol, that only a devotee' of the Freethinkers could navigate it. Around the planet, in stealthed spaceships set observers from older, grander, psionic civilizations, and they wondered if the meaning and symbols were essential to the learning of the psi powers the humans had stumbled into, or if they were simply fluffery attached to real technique.
The humans saw it as absolutely essential. And the Freethinking Ways were diametrically opposed to all the ways of the Old Gods. Indeed, each stage of the rituals which led the novice into his psi power included a bit of ritual which was a defamation of one of the Old Gods.
The Guildsmen sought to defuse the antagonism they also stoked. They created scorn, and when that was met by hostility, they complained, and created various rhetorical defenses so as to make the vast majority of the 'insensate sheep' feel awkward. Of course, some few of the 'sheep' really did not care what the Bright Young Things thought, and it became dangerous for a BYT to venture into certain countries and areas of certain cities.
It was a cultural war between a young, rich, and stylish, and international elite aided by psi power against the vast majority of humanity.
The Guild, which proclaimed the highest ideals, was also aided by the lowest of means. Guildmembers entetaining second thoughts had the tendency to drop cigars on their beds and burn themselves alive. Seeing as most Guildmembers were, shall we say, a tad cowardly, a few demonstrations went a long way.
The war continued, but we take another turn.
A certain family, the De Noveuse and their friends/retainers (friends in name, retainers in truth) went further than most in their search of psi power. They took greater risks, and they had more logical thinkers who studied the problem in depth and planned experiments on these theories. Its not that they were mad scientists or infernal priests although they had elements of both, but its clear they lacked a sense of solid moral boundaries.
One point about the Rituals that struck Claire De Noveuse, a powerful pschyic, was how the gain in power attended the defamation of the Old Gods. Since she did not believe in such, she theorized that they represented certain primal forces instead of being the guardians and utilizers of such forces. And so, she should find other primal forces and assert her mastery over them.
She bought a factory, and destroyed it in a ritual with explosives. This led to some insights into telekinesis which was not a common ability for the Guild who had most concerned themselves with reading thoughts, and compellign wills and sending impressions. Of course, the ancient minds in other star systems had far greater powers. And if they had been paying closer attention, they would certainly have saved the Multiverse from a significant problem by killing Claire De Noveuse.
She then turned to studying storms, but could find no way to defile the lightning to let her into its secrets. So after a year of fruitless study, she found herself helping one of the maids in her mansion aka castle give 'birth' to a miscarriage. And it was then that she saw the beginnings of a new way forward.
Being an attractive woman, it was not hard for Claire to get pregnant. She marvelled at the strange feelings this brought forth, and was even mildly tempted to turn back from her wickedness. In the end, she put aside the whimsy, and got down to business, and murdered her newborn.
And with that, the defamation of life, she was able to disconnect herself from her body, to project herself into other bodies. Oh, not immediately, but the understanding came.
And with it, came the De Noveuse's rise to power. She brought her family in, taught them her rituals, and bound them to her with unbreakable oaths. And then she spread the Newest Understanding to the others in the Movement. And there the scales in the long war began to tilt for when a man could be controlled from a distance to open fire on his conspirators against the BYTie-bits...the bittie-bits as they were called by their enemies, it was very hard for the followers of the old ways to stand.
For the elite, it was infanticide, but they found this too hard a pill for the people to swallow, so they settled for abortion. And with that, some of the New Projectives found another level to their power.
Claire De Noveuse never did for she was happy being the uncrowned queen of the world and of darkness.
But some, with flexible and far-reaching minds stretched out their projective talent, and went sideways. They lost contact with their bodies, and many died, but a few were able to find bodies in other dimensions. And they were able to send back word. New worlds. Strange peoples. Exotic cuisines.
And so at first it was ten, and then twenty, and then a hundred, and soon the Otherdimensional Projectives learned how to avoid dimensions they would not prosper in because of bias. They learned to how to trade bodies before death. And after some time, they had children who were as they were.
And then one of them met a verser. The verser was not impressed. We don't know his or her name. We just know they fought. This happened several other times, and rumors began to spread from projective to projective when they met, and from verser to verser when they met.
But it was still just a hand on the horizon.
And then several projectives met a couple versers. And these versers were different. They did not care about the moral judgment of stealing bodies. But the projectives manners were high-handed to say the least. The war between versers and projectives really got going because the projectives were snooty, and the versers were arrogant. The projectives said 'step aside, peasant' and the versers drew their weapons and refused. One projective died outright without chance of coming back.
And there the flame was lit and raced to the gunpowder.
The high-ranking projectives found out, and sent messages when they could by various means to others, and it was war. The versers had less efficent means of communication, but soon enough, several circles of versers, the groups that gather, all knew of a new threat.
And at first, it looked like the verser might be the truly dangerous one here because he was truly immortal. OTOH, the projective had the ability to change bodies at will,and was usually adept at controlling political power. It was the confrontation of the Gunslinger vs. the Mayor and his assistants. But then one projective discovered how to jump into a verser's head, and drive him out.
Its a mess now, with several 'verser' projectives, and several versers who've learned projective skills (and one that knew them before the projectives and is baffled that the projectives engage in such outre' rituals to do basic psi work.) One theorist of battles thinks that there are up to two hundred combatants counting both sides in a war that stretches out over nealry a hundred dimensions. Its an intermittent war that flares hot, and goes dim, and sometimes cold.
Most of the projectives are relatively near each other in multi-dimensional space which means that if you find one, you're likely to find others 'nearby'. Of course, there are far more versers that have never even met the Projectives.
And the Projectives don't have a real good grasp on the size of the Verse. They have two dominant theories. One...the more scientifically respesctable one...the Verse is a thousand dimensions strong. Two...the more appealing to them and thus the more popular with them in numbers of adherents....these other dimensions are not quite real. This flows from their POV back home when they viewed the sufferings and dignity of other humans who were not BYT's as not quite human.
Good.
A couple points.
First, the idea of a non-verser non-supernatural evil that can easily reach all universes is fraught with story problems. The two biggest are worth mentioning.
If you introduce such a power, you infect all the universes with it, and the story becomes limited. Sliders made this mistake with its Cro Mags, who could track and follow the team wherever they went, and once that happened it was always about the war against the Cro Mags instead of the events within the universe.
Then once you have done that, you must ultimately have the enemy arrive at the original starting universe. Never mind the problem that versers don't go home; the villains will be able to get there, and will want to get there if they are fighting against versers, because they're going to want to understand where and how versers originate. But when Sliders tells us that the Cro Mags are invading our home universe, we've just had our disbelief suspenders snapped--up to that point, all of this was possible because Quinn and company had left our "normal" universe and were exploring various variant versions, but now the "normal" universe had been invaded, and the story shifted sharply to something more like "V". Quinn was no longer from our world; he was from that other world that the Cro Mags were invading. So, too, when your interdimensional villains reach Earth, we know that they're not here, so we have a break with reality.
The way to prevent this is to limit the powers of the villains to action within a multiverse of related universes--not all the universes in the multiverse, but a batch that are more closely connected to each other. This is the trick that makes possible such stories as the Jet Li film The One: yes, the divergents do become more powerful as they decrease in number, but only within this limited number of universes.
*****
The other aspect that is troubling me is the impression of using magic ritual to enhance psionic power. This is particularly difficult given that those using the magic ritual do not believe in the supernatural, and so cannot perform magic; otherwise I would simply say that they are creating powerful magic spells to give themselves psionic abilities.
The use of drugs and self-dehumanization to break down barriers in the mind and so gain psionic power is viable, but some of what you've included here doesn't really fit that very well. That is, killing an infant is dehumanizing, but demolishing a factory probably is not. What makes the factory demolition "work" as an element of something is that it is a sacrifice in a ritual--and that means magic. I'm not sure how to get around that part.
*****
Incidentally, the penalty for telepathic or other psionic skills (including possessions) across universe boundaries is stated at -50, although the most common botch is reaching the wrong universe. That means experienced versers could develop similar trans-universe communication skills by reaching high levels in the skills and high bias in psionics, and taking the risk of making such contact.
Also, it's a rule that you can't permanently dissociate a verser from his body. You can control it, but he's always connected to it (his spirit/mind is equipment that belongs to his body and cannot be disowned). Thus Projectives that captured a Verser body would have to deal with the verser spirit/mind perpetually, and could be ejected eventually.
--M. J. Young
I'm fine with a limited multiverse. I'd probably make it so that the Projectives theory of a thousand dimensions is correct for the Projectives Limited Multiverse. This could be a chance for a verser to learn more about Multiversal Physics as the Projectives would have good math to show why there is only a thousand universes, but the verser could possibly know from personal experience and from the list of universes with their descriptions that there were versers the Projectives were not counting. I'd say the PLM is all earth like planets, and so a verser that had been to The Web would know better. And that could lead him to an understanding of Small Multiverses.
And if I'm going to have a Small Multiverse, I might as well make the whole thing high psi, and then I can delete the scouting ability the Projectives have. It was there so that the Projective when he jumped where he knew not would not end up jumping into a universe that did not support his existence. I'll have the other biases wobble up and down.
The factory is meant to suggest a dominance over physical matter. It could be also that it opens the mind to the joys of pure destruction and so enables pyrokinesis. However, its not the best example, and I could look for another one.
I think I ought to add that they do their transuniversal contacts with severe limits to bonus their effort. 1)Fast for twenty-four hours (this is not so much ritual as getting the mind disconnected from the body). 2)Said person is more vulnerable to other psionic effects at such time because they are less grounded in their body. This is related to the idea that the insensitive lout might be able to walk right through a telepathic barrier that a smarter poet might almost die from. The idea is that the body grounds the mind in mundane reality, and as one book I've read suggested the best treatment for a pschyic shock is a chocolate bar and a blanket. 3)Exhaustion of mental force for a day (which must include sleep)--aka temporarily lose @5 to Intuition, Willpower, and @3 to Intelligence. 4)Physical exhaustion for two hours afterwards aka all basic physical tasks require Simple Stamina Checks for going to the bathroom or getting a drink of water. More difficult and we go to Difficult Stamina Checks.
I think this would balance out the +50, and it would help explain why the Projectives don't use this ability that often.
I do think that the possession across universal boundaries might be cheaper because this is more of "I'm dumping my old body and getting a new one." In order to do the first Projective leap, the novice Projective to onlookers dies as his body remains behind, and his heart and brain stop functioning.
I don't have a problem with a verser trying to get his body back from a Projective thief. That would work quite well with the story.
My recollection is that psionic possession of another body means leaving your body empty at the baseline; if you maintain both bodies, that's remote control, and actually lower on the bias line, but it does not necessarily give sensory info (a separate skill). The notion that the body appears to all tests dead is a bit extreme but not inconsistent; comatose would be the usual appearance.
--M. J. Young
I would say the body is dead unless it gets quickly reinhabited. Projectives leave a long string of dead bodies behind them.
Now it is true that you could have something more like a real empire if you were able to go back home, report to your superiors, and then jump back into your other body in the other dimension.
People like Clair De Noveuse would have possession. The extradimensionals leave at least one dead body behind (and you said versers can't be dispossessed permanently so perhaps no one can, and the body is returned back to its owner when the Proj. is tired of it.)