Red Rain

The Red Rain is an event that occurred worldwide shortly following the defeat of Draven Nosk. Caused by a figure presumed to be the god Nethys in exchange for sparing the world its destruction as a result of the Sphere of Annihilation merging with Nosk's Fusion Core, or the timeline being rewritten as a result of Nosk's experiment (this is unclear, as Nethys was being vague). With the intent of allowing magic to rule the world, Nethys hoped to subvert the inert dominant force of humanity by imbuing the race with inherent magic.

This was achieved through a global shower of red rain, which caused intense physical in pain in humans and granted each one a magical ability. Notably, not only were half-human hybrids left unaffected, humans with nonhuman ancestry, such as Princess Saldri, felt no effect from the phenomena. The fact that a former ratkin reincarnated as a human was affected would seem to indicate the it is biological purity, not historical or ancestral purity, that caused the difference.