Answer:
I start with an E end with an E and have a letter in me.
Break me and I am better immediately set and harder to be broken again.
Sometimes I annoy you, sometimes you can't live without me. But no matter how hard you try, you can't destroy me. What am I?
I can generate fear and some say I come out of your ears. I am as quiet as a mouse but not welcomed in the house.
The more of me there is the less you see.
What made Cyclops quit teaching?