Answer:
I open wide and tight I shut, Sharp am I and paper-cut fingers too, so do take care, I'm good and bad, so best beware.
I have it, I don’t share it. If I share it, I don’t have it. What is it?
Dies half its life. Lives the rest. Dances without music. Breathes without breath.
It's like food but water kills it. What is it?
Each morning I appear to lie at your feet, all day I follow no matter how fast you run. Yet I nearly perish in the midday sun.
If you can spot one of these eastern warriors, it means they're not doing their job right.