Answer:
I am a type of weapon for SCI-FI characters
Glittering points that downward thrust. Sparkling spears that never rust.
Used left or right I get to travel over cobblestone or gravel. Used up I vie for sweet success used down I cause men great duress.
You can drop me from the tallest building and I’ll be fine, but if you drop me in water I die. What am I?
I like to twirl my body but keep my head up high. After I go in, everything becomes tight. What am I?
It weighs next to nothing but no one can hold it for long. What is it?