>>718070356
!!! SPOILERS AHEAD !!!
Short-ish version.
In Drakengard 1 (parallel universe relatively similar to ours till some middle ages date I don't remember) during the final fight between MC and his dragon vs Queen-beast, they teleported to 'our' universe's present Tokyo.
MC+dragon killed Queen beast, got killed by nip airforce (I shit you not).
Disintegrating body of Queen-beast didn't disappear but fine particles dispersed into air, introducing 'maso' - magic particles to world without magic.
Every human who came into contact with 'maso' got a choice - turn to salt statue (a.k.a. White Chlorination Syndrome) or become a beast hell bent on destroying humanity.
Beast became Legion, they got a commander, crusades against them started etc.... there's a lot of shit that happened but the main problem for humanity's survival were the magic particles dispersed in atmosphere.
They came up with plan to divide human soul and body, create physical bodies (replicants) without souls (so they wouldn't be affected by maso). Replicants would clean up magic from the world and once magic is gone, the souls would reunite with bodies.
Shit went wrong for reason you'll learn when you finish your Nier run.
Backstory is pretty wild.