Disclaimer: Sasuke isn't mine, and even if he were, I would be angry with him for being a mean person :P
MASK.
Sasuke.
I wear a mask so people cannot use my emotions against me.
Too many times have I let my true self show only to be kicked in the face because of it.
Like when I showed my concern for that blond dobe while fighting Haku. Had I not cared, had I pretended he meant nothing to me—Haku wouldn't have focussed on attacking Naruto to stop me. He knew I would protect him, and that made me weak.
My mask is indifference. Indifference is the easiest face to keep. It keeps me in check.
Someone dies, I show no emotion.
Someone is injured, I do not care.
Someone is missing, it doesn't concern me.
No matter what happens, it is of no importance. My mask keeps me numb to all the pains in the world.
If I do not feel, I do not have to fear being hurt. Anger and indifference are the only emotions I will express.
The only people capable of breaking my mask are Team Seven. Naruto, Sakura, and Kakashi.
Yes, even that damned perverted bastard can chip my mask, even just a little.
Sakura cares for me too much, and it hurts. It hurts to know I cannot care for her as much as she does for me.
I want to care, but caring causes pain. So the mask hides my feelings. It keeps me safe.
Naruto works at my mask the most. He rips at it. Tears it. Claws it. Bites it.
He'll get a grip on it and he won't let go.
I hate him.
I hate them all.
I have to hate them to keep the pain away.
Hurting others is better. Better to hurt them before they hurt you.
I don't want to care for anyone, because if they are injured—if they die...
My mask will beak.
My mask resembles Haku's Mist nin mask. One face. One expression. One feeling.
I do not want to lose this mask.
I cannot show emotion, especially when I go to face Itachi.
I am weak because I feel. He is strong because he does not.
The mask hides the pain.
The fear.
The emptiness.
I cannot feel. I mustn't feel.
Those who wear masks do so to hide who they are. I do it to shield myself from becoming who I must not become.
Were people to know I felt more than I showed, I would not be able to avenge my clan. I would begin to care for those who are unworthy. They do not deserve my feelings, they do not deserve for me to care.
No one is worthy of my love.
I have only one purpose: to avenge my clan.
This is my purpose.
This is all I must care about.
It's in my bones.
It's in my blood.
It's what I am. Who I've become.
An Avenger.
The mask hides Sasuke. He no longer exists. He died when Itachi killed his clan.
The Avenger is the only one who remains.
I don't want to care.
I can't.
I won't!