Twice the cutting power! (Cem)

Proverb used to convince one of not using a weapon (literal or figuritive) because it may come back and hurt yourself. Rather useless especially with the fact that one can learn how to use a double edge sword (literal or figuritive) effectively.

a double edge sword is simply sword with two sharp sides, often it was used on broad swords, it is often believed of by people that broad swords are these long, straight swords, that look something like this
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==|------->
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but that actually qualifies as a double edge sword

"Double edge sword" is a silly overused proverb that makes little sense.

Well pre-dating the Blue Steel look of Zoolander fame, this phrase refers to something entirely unrelated: a song of such depressing mood and portent that it could, figuratively speaking, drive you to put a double-edge blue steel razor blade to a very unhealthy use.

Double-Edged come from an ancient word meaning (pure rage). It would normally be used to describe something annoying or out of order. If someone is double-edged then they would be an annoying piece of shit and a waste of space.

Some use Double-edged as a good thing, this use of the world is completely wrong and these people are morons.

When something doesn't really work in your favor, but also sort of works against your enemy.