Answer:
I am the greatest teacher out of them all, but alas in the end I kill my pupils.
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.
Lighter than what I am made of, More of me is hidden Than is seen.
When set loose I fly away. Never so cursed as when I go astray.
The sharp slim blade, that cuts the wind.
I can only be played on a windy day
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?