The Mysterious Killer [Crossover]

When I was nine, my dad suddenly fell apart.

That's right. The tall, gentle man who was obedient and sweet around Mom turned into a pile of lumber right in front of me.

From that day on, Mom and I shared a secret: my dad was nothing but an automaton, and Mom was one of the few witches left in the world.

So where did I come from?

...At the time, I knew nothing about biology, so I never asked that question.

The following Christmas, Mom disappeared from my life. The last thing she said to me was:

"Come find me on the other side of the world."

I got out of bed and tapped the dining table as I passed it. "Good morning, Dad."

Naturally, there was no reply. This dining table was made from the lumber left behind when my dad, that is, the automaton, fell apart. Mom said I could think of it as my dad.

"My dad is a table!"

When I was little, saying that earned me curious and envious looks at first, because my dad was different from everyone else's.

But once we all grew up, no one envied me anymore. They would only say behind my back, "She's a girl without a dad."

Nonsense. I'm actually a girl without a mom. Dad has always been here with me.

Primarily Type-Moon, with a touch of Lovecraftian elements

Female lead is a person made by the Holy Grail, a mysterious killer, first-person narration

An idea I'm saving for later