What would you do if someone somewhere was hurting your child?
You would take your child away from its pain and kill whoever it was that was causing your loved one misery.
What if the person being hurt was someone you didn't know? Attacked at three in the morning in an alley outside a pub, a complete stranger, what would you do? Most beings in the universe would run.
It takes a great person, as a member of the human race, to override that urge to run. They would run and hide, and feel ashamed of their cowardice. They would spend the next few days convincing themselves that nothing could have been done, and they would have wasted their time and probably gotten themselves hurt in the process. They lull themselves into a false sense of security, content to live with their shame, all because they ran.
But there is a man, known to some as the Sainted Physician, known to others as the Oncoming Storm, known to many as the Doctor, and known to the lucky as a friend. A man who never would.
The Doctor is a Time Lord, an alien from a planet soaked in blood and ash, dead to all but itself. Content to recant their emotions, the Time Lord race were proud overseers of time itself. The Doctor ran from them because he did not believe in what they stood for. He thought that emotions were essential parts of living and he refused to stand by and watch the lack of emotion in his people doom so many others. He cast himself out from his own race, content to travel among the stars, saving people and planets from peril with two hearts that are both bigger on the inside.
He has taken many companions on his journey, with whom he shared the stars and the wonders of the universe. Sometimes they got hurt. And sometimes they died. But he would never forget them, not even for a second, because he knows how important memories are when the ones you love never live as long as you do. He refuses to forget because they are all so precious to him.
The Doctor fights across time, defending those who cannot defend themselves. He never stops, he never stays, and he never asks to be thanked. To his enemies, he is a cold, hard soldier. To his friends, he is a warm, caring constant. A preserver of life, he offers redemption to any and all, no matter their previous crimes. He does not believe that any deserve to die. He mourns all loss of life, no matter the source.
Nevertheless, he's always sad. He is haunted by shadows of the universe and shadows of his past. His daily life stays one step ahead of his history of regret and sadness. He runs from his silhouette on the ground, afraid of what he will find behind him. He is unaware that these shadows only live by the light that he casts. This ever encompassing light that drives away monsters, demons, and fear. The light that the people of the universe look to when they have no one else.
Because the Doctor... He is like fire and ice and rage. He's like the night and the storm in the heart of the sun. He is ancient and forever. He burns at the center of time and can see the turn of the universe...
And he's wonderful.
And if there's one thing in the whole, wide universe that I believe in, just one...
I believe in him.