Human slayer (fairy tail )

Everyone knows about
dragon slayer,
god slayer,
and demon user

...but...

no one know about
human slayer.

Human slayer is a god and demon
combination.
There are only one thing they have to do and that is kill every
human in the world.
They only have forty of them
in the world.
The leader is a girl that have power
to control the living things.
She can make people dead or alive
if she wants.

And then human slayer era begins!