Well....

It isn't a proper Final Fantasy unless a purehearted shrine maiden gets murdered.

Preferably a shrine maiden, and preferably sacrificed.

Spoilers for proof:
ARR has its Minfillia
HW had its... Iceheart?

SB had.... uhhh... Nothing, except everyone's opinion on Lyse?

Shadowbringers had Minfillia, again
Endwalker had Hydaelin and Minfillia again.

Dawntrail has.... um, WoL's self-esteem, I guess? And Erenville's mother, who does not really fit the type.