Answer:
Slayer of regrets, old and new, sought by many, found by few.
What word starts with 'E', ends with 'E', but only has one letter? It is not the letter 'E'.
This thing all things devours: Birds, beasts, trees, flowers; Gnaws iron, bites steel; Grinds hard stones to meal; Slays king, ruins town, And beats high mountains down.
I am seen in the water. If seen in the sky, I am in the rainbow, a jay's feather, and lapis lazuli.
My voice is tender, my waist is slender and I'm often invited to play. Yet wherever I go, I must take my bow or else I have nothing to say.
I can only be played on a windy day
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?