Crow. (A original story(?))

I don't know why I keep doing these.
(This is not based on Demon Slayer i started writing this long before i knew what Demon Slayer was)
Lucas Newlin lives in a world where it has three beings.
Humans, Hunters, and Demons.
Demons are evil beings. They are born evil and will always be evil. They can shapeshift into anything and blend in with the humans.
Hunters are humans with special weapons that allow them to kill Demons.
Lucas is a hunter. His little sister's life was taken from the evil and so Lucas wants to kill every single Demon out there.
But there is only one rule:
Trust no one, not even yourself.