The Megalopolis of Scythe and Key

The city of Kakuseiyoru slept peacefully, situated in a location where witches could walk without the Anti-Magic Toxin being buried deep in their souls so potently that witches couldn't exist.

And while that certainly was a blessing, the dawning of night awakened true horrors that spawned an unknown serial killer dashing the sidewalks and claiming the lives of victims with no explainable cause. No one was able to deduce who was behind the magical murders that were seemingly impossible for a human...

...but not everyone is going to give up that easily. To uncover the cause, in this magical world of mystery and fantasy, two dedicated heroines form together in order to unravel the mystery and put an end to it once and for all.

Note: This is in a separate AU where Rokkenjima does NOT exist, so the events of Umineko never took place. The setting is especially different, instead taking place in the city in Umineko rather than the island. There are other noticeable differences that will be disclosed and apparent as you continue to read the story.