I can be used for simple things, 

Carving, cutlery and pain.

Doctors use a form of me, when they cut into your brain.

I’m used in art, as both the method and subject,

I am even some military men’s favourite object.

I have many names in many tongues,

I’ll cause the smell of blood to fill your lungs.

But of all my many uses,

My favourite is betrayal. 

I am your shadows gun.