A/Ns: I'm personally not a huge fan of 11, but I feel that this suits him best. Well, eh, enjoy?
"...all the people who have died because of my mercy!"
Breathing, perhaps. Certainly breathing, with beating hearts, and eyes to see with. A mouth to speak his clever mind, and ears to hear. Fine and dandy that was, but suppose... Suppose there was something else, but suppose it wasn't there.
A soul to give a special kind of life; the sort where you know that you're more than just a sack of skin and bone. Such delicate little things, they are... Wastes of space, some might say, but so full of life! That's why he loved them most, the humans. Original, teeming in full-bloom, and so lively. He longed for that.
What must it feel like, he wonders, to be human? Perhaps it's the nature of a Time Lord to feel so empty. He knows he's wrong, only making excuses.
What could be left of him in the end? Two hearts made of love with a hollow and sad beat in his chest. He contemplates cutting them out every day, every night, because they have caused too much pain. Years upon years of life, so very much to see, but he isn't sure there's anything left for him. In fact, he's almost certain of it. Throughout his life, pain and misery have been the constant and faithful companions at his side. He lives in the past because he's afraid of what the future brings; but even more so, he fears the past and hangs his guilty head, washes his blood-soaked hands. He runs blindly from it all.
He's not sure what he is anymore, if was ever something. No, he knows he used to be something: innocent. Before the blood and screaming, he was happy and at peace. So many things have changed, and so fast, it seems. "Regretful" is the only way he can describe himself. Dragging his loved ones full-on into the face of danger, but he can't be alone, he can't bear it.
There's only one thing he knows, forgetting his clever mind, and charming smile. That's just a game. Hating yourself a little more each day. Getting knocked down a peg further, falling to places so low they are unimaginable. To feel as he is dissolving, less than air; colorless and odorless. Invisible.
Negative space. That is the Doctor.
UPDATE: Special thanks to ChocolateTeapot who pointed out the error in this. xD'