Answer:
I am the ultimate killing machine used not once but TWICE I can be made by humans.
What has no beginning, end, or middle?
I always have to work with something in my eye. What am I?
I am full of holes but still hold water. What am I?
Lovely and round, I shine with pale light, Grown in the darkness, a ladyβs delight.
No matter how little or how much you use me, you change me every month.