Didn't that only work on members of one tiny nation's royal family? Like, that was a major plot point in the comic where they debuted the Geo-Force (Markovia's Last Stand!): "[the Geo-Force] can be retained only by blood members of the Markovian royal family!" Direct quote from the ruler of Markovia, there.
The read I got was that the whole thing was some "the land recognizes the blood of kings" shit gussied up in technobabble to keep it from literally being a magical geomantic empowerment ritual. My only other guess is that somebody in the lineage fucked an earth elemental, and the scientist lady accidentally figured out how to magnify a person's elemental heritage (which would still be useful, but could lead to things like "Hey, turns out your ancestors were Nurglite cultists! Have fun with your new Ebola powers!")
My memory, which admittedly can be fuzzy, considering that whole storyline was in the early 80s, is that it was an artificial limit put in as a safeguard- She made that device to give Brion Markov powers, other people need not apply.
To someone with the entire New God database and/or access to the entire Oan catalog of science, that would seem like an easy limit to remove.
If Phantasmo is anything to go by, partially earth elemental humans gain the ability to phase through matter, a power that is not in Brion's thematically linked grab bag powers.
Regardless, having the genes of someone related to the Markov family is hardly a problem, since 2 out of 3 of Terra 2's origin is her not being related to Brion but being given Terra 1's genes.
For those not familiar with the Terras- Terra 1 was Brion's illegitimate half sister, she was either crazy, evil, drugged or a combination thereof, and died.
Terra 2 was either Terra 1 resurrected from the dead, a random girl abducted and given Terra's genes and powers, or a subterrestrial Stratan who volunteered to have her DNA change her species so that she can be a Terra 1 doppelganger who had issues because she had at least two sets of false memories in her brain.
Note- Stratans have an interesting origin. A giant in a spacesuit crashed landed on Earth, killing it (or already dead), buried by time and its landing, the technology in its suit prevented his body from decaying in normal fashion, instead its life support system caused the giant's body to evolve into a self contained ecosystem, and eventually an underground city (Strata) comprised of multiple intelligent species.
The Astronaut God's blood has mutative properties, giving both Terra 2 and Terra 3 their geokinetic powers (Terra 3 being a stratan who was mutated by the blood, then remade into a human to go superhero on the surface, they however never made her look like Terra or make her believe she was Terra) it also gave a human the ability to turn into minerals similar to the Absorbing Man, and his girlfriend a crystaline form that unfortunately for her shattered.
If Zoat was using the New Gods are giants thing from the comics, I'd suggest that the Astronaut God might be a New God with geocentric powers who crash landed on Earth.
However since Zoat hasn't included Terra 1 worrying about Terra 2 and 3 is probably jumping the gun.
