A Cannon Fodder NPC Won't Meet a Yandere Heroine

I transmigrated into a fantasy world of swords and magic, only to be forced by a cheap System to become a cannon-fodder NPC?!

Knowing that the future holds nothing but a Bad End, I, a transmigrator, resolutely set out to change things.

But somehow, the results aren't quite what I hoped for.

Why has the gentle and steadfast Saintess grown a pair of succubus wings?

Why is the aloof imperial princess actually a scheming, shameless woman?

And how did the holy sword in the hands of the righteous and kind heroine turn into a cleaver?

...All I wanted was to get rid of my death flags. How did things end up like this...?