↳Companion Series: Rose Tyler
"Get out of the way! Rose, get out of the way now!"
"No. I won’t let you do this."
"That thing killed hundreds of people… I’ve got to do this. I’ve got to end it! The Daleks destroyed my home, my people! I’ve got nothing left!"
"Look at it… It’s the sunlight. That’s all it wants.”
Rose’s recklessness was a double sided coin. In any other circumstance showing mercy to a Dalek would have cost her her life, but injured, this Dalek used her DNA to begin rebuilding. Now infected with humanity, it began to change - to feel.
So when the Doctor was set to kill it, she stops him, "It’s the sunlight. That’s all it wants." She tells him. And that’s when the Doctor remembers how much he had wanted the same thing. Just like this Dalek, he had blood on his hands, and he wasn’t even the one programmed from birth to kill. But Rose had been there to believe in him. She had left everyone without explanation to follow an angry and wounded man, but that recklessness had changed his life. Her impulse could have easily meant her death, but instead, the only thing that died was his isolation. She had, with her warm smile and ready embrace, taught him how to feel again. And he had begun to see the light again because Rose had taken that chance. So he put the gun down. Because he was changing too.
She’s too human. It’s like RTD said she humanizes the Doctor as he time lords her.