Genasi are normally "plane-touched" by the power of the planes of the elements: earth, fire, wind, water, and a smattering of others. In my science fantasy setting (with a stronger emphasis on the sci-fi since there are only psionics and occult power, no arcane or divine magic), creatures very similar to genasi exist. They descend from an extinct humanity and are the dominant race of a post-apocalyptic Earth 2000 years in the future, but they were "created" from the four fundamental interactions of nature: gravitational, electromagnetic, strong nuclear, and weak nuclear. This, I think, is a really cool concept, but I need some stuff to be fleshed out:
-How exactly were these guys created, and why? Did they come from humanity's ancient scientific pursuits (which was a space-faring civilization before its collapse millennia ago), or were creatures with extraterrestrial---or extraplanar (ultraterrestrial)---responsible for their creation? Other planes are a thing in this setting, but traditional fantasy extraplanar creatures like angels and demons and such aren't confirmed to exist, and gods, if they exist, are nowhere to be seen.
-What exactly is the nature of the stuff that makes them "genasi"? Is it from the actual four fundamental interactions of nature in the Material Plane, or, similar to their fantasy cousins, it comes from the "planes" of gravity, the plane of electromagnetism, and strong and nuclear force?
-What would the sub-races actually be called? Like how there are the airsouls, watersouls, firesouls, etc.
-What would each of them look like?
I'm open to Genasi coming from other forces of nature, as long as they're not from supernatural origins.
Lenzsouls (electromagnetic, Lenz's law), Gravisouls (got nothin here), Mesonsouls, Pionsouls or Yukawasouls (strong nuclear particles/theorist who predicted them), Fermionsouls (weak nuclear interactions).
Flavor them as humans who attempted to unify themselves with primal forces in order to elevate their control over the natural world.
They were able to harness the four fundamental forces and bind themselves to them, effectively becoming variations of "Material-Plane Outsiders".
Have the Electromagnetics radiate slightly more heat than normal humans, and have magnetic material react to their presence flavor-wise.
Gravities have slighter higher/lower weight than normal.
StrongNuclears are heavier, have them enjoy greatly increased density of body.
WeakNuclears are practically decay. Have them give penalties to disease or fortitude to themselves and creatures nearby.
Appearance-wise, can't think of much for them.