Seed of Evil

In the famous "water city" of Somden, a noxious gas began to billow from a rivercave.
The pollution destroyed half the town. Its people became lawless thieves.
Monsters made off with the last few good men -- the fathers of a local parish.
Sisters were dispatched as relief. One was the protagonist... but en route to Somden,
she was snatched by the monsters too.

Somehow she was saved but, from her head where the monster transgressed her
a strange flower had blossomed.
She made her way to the rivercave and roamed deep, save the fathers, to investage the flower......