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Royal Blood can sometimes have supernatural properties
We can never truly eradicate the coronavirus, but we can suppress its threat like influenza
I'd file it under Die or Fly with the Bene Gesserit's tests from from Dune: They're masters of Enlightenment Superpowers with a heavy lean toward Biomanipulation, so to prove that they've achieved the basics of self-control, a novice must stand motionless with their hand in a pain box and a poisoned needle at their neck as motivation not to flinch. (The final graduation? Drink a jug of neurotoxins and alter their own biochemistry to neutralize them.)
Edited by Scorpion451
There's a fruit that's deadly if eaten by anyone who's not a member of the royal bloodline, so it is used to test if someone is of royal blood.