Answer:
I have rivers without water. Forests without trees. Mountains without rocks. Towns without houses.
It holds most knowledge that has ever been said. But is not the brain, is not the head. To feathers and their masters, it's both bane and boonΒ One empty, and one full.
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard.
Break it and it is better, immediately set and harder to break again.
Useful tool for who in darkness dwell. Within you, corrupting like a deadly spell.
If you can spot one of these eastern warriors, it means they're not doing their job right.