Answer:
We are all around, yet to us you are half blind. Sunlight makes us invisible, and difficult to find.
Slayer of regrets, old and new, sought by many, found by few.
What is as big as you are and yet does not weight anything?
Useful tool for who in darkness dwell. Within you, corrupting like a deadly spell.
My first is nothing but a nameอพ my second is more smallอพ my whole is of so little fame it has no name at all.
I stay where I am when I go off. What am I?
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?