She gave him life, and so in fair exchange, he gave her a quick and simple death. [Itachi character study]
Her beauty seems ethereal in the moonlight, a dim foggy shadow of its usual vibrance. Their family is a beautiful one, and strong. She wanted him to be strong. They all did. And he has found a way to make himself so. Surely, they will not blame him for realizing their own dreams.
She in particular, who pushed him so hard to be strong and smart like her.
The beating of her heart is painfully loud against his little brother's shallow gasps, rasping in the otherwise tranquil bedroom. Her mouth opens, works silently as he raises his arms. Who is this weak, abject creature? She is not strong, like she wanted him to believe: she is not his mother.
Rise and fall, rise and fall. The terror of a cornered animal. Rise and fall.
When he brings the blade down and listens analytically to the slick sound of metal severing flesh and tendon and bone, it does not make him any stronger, but leaves him somehow unsatisfied.
He came here seeking to learn the experience of killing a loved one, but by the time he arrived she had cheated him yet again by fleeing her own mind, by leaving the shell of herself empty. And there is nothing.
Across the room, Sasuke screams and collapses, but the sound is inaudible. The pounding heartbeat against which he once nursed is gone, and no sound can be heard.
He knows he must kill many, many more to be strong, because the blood spattered on his clothes and hands and face makes him feel sick. So he knows, he is still weak.