Answer:
What flares up and does a lot of good, and when it dies is just a piece of wood?
A precious stone, as clear as diamond. Seek it out whilst the sun's near the horizon. Though you can walk on water with its power, Try to keep it, and it'll vanish within an hour.
What doesn't get any wetter, no matter how much rain falls on it?
I follow the orders of only two. I respect the work of only two. I am in constant battles with many, Though one surpassed them all. With forces joined, We created hell, Until our mutual enemy fell. Who am I?
I'm full of holes, yet I'm full of water.
When is it bad luck to see a black cat?