In an RTS game this troper is devising, the leaders of the forces of
Agartha are like this; they were originally a bunch of EvilSorcerer types from
the old Tibetan Empire circa 600s CE, who had very powerful magic and gained immortality, but when Buddhism became more or less fully entrenched in Tibet the sorcerers had less and less influence, and in the end were hunted down, escaping through MassTeleportation to the planet Alfheim, where they fought against the
Ljosalfar who drove the formerly-human sorcerers underground. After a group of American soldiers stationed near a backwater Arizona town ''along with the townspeople'' ended up in a MassTeleportation of their own (the base was studying
a weird, harder-than-diamond object called a Godstone, out of the analogy "God only knows how it's harder than diamonds" that fell to Earth) got teleported because of a SummoningRitual to retrieve the Godstone back to Alfheim
went too well. The Agarthans, from scrying human culture,
start growing little grey men to serve as technological users (guns etc) since the master Agarthans themselves
though powerful magically have very little clue about human-type technology - and also ''to get the humans scared'', since by that time the Agarthans forgot over the centuries even what it was like to be actually human, ''even to the tiny detail of
really having to go to the toilet'' - however,
the Outer God that gave the Agarthans their power
is evil and nothing else and needs what is left of the sorcerers' humanness to make plans that actually would work...