It can pierce the best armor and make swords crumble with a rub, yet for all its power It can't harm a wooden club.

Answer: rust

More Difficult Riddles with answers

More Difficult Riddles

It can't be seen, can't be felt, can't be heard, and can't be smelt. It lies behind stars and under hills, And empty holes it fills. It comes first and follows after, Ends life, and kills laughter. What is it?
It cannot be seen, cannot be felt, Cannot be heard, cannot be smelt. It lies behind stars and under hills And empty holes it fills. It comes first and follows after, Ends life, kills laughter.
It doesn't live within a house, nor does it live without. Most will use it when they come in, and again when they go out.
It flies when it's on and floats coming off.
It floats over the land, It cuts the tallest mountain, Its voice is like a fountain, Its body like a snake, Will flow into a lake.
It happens when something has been cut with H2O.
It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.
It holds no blessings in disguise. Its rhymes are aimed at your demise, it's cast only to ruin, Whatever you are doin'.
It is a 5 letter word if you take away first letter it is something you get from sun, if you remove second letter you will get something to eat, if you remove third letter you get a word you use in pointing at and if you remove the fourth letter you get something to drink. What is it?
It is a path of cow juice spread across the sky but cannot be seen by the naked eye
It is a sound of empty, speak and it'll talk back plenty. But all the more you yack, you'll get the same words back.