Thanks, I tried a little something to see if it worked. It was a rare occasion, but hey, if Ianto likes it..
Yeah- he did. You came back when you shouldn't have, you had absorbed the Time Vortex, the heart of his TARDIS. By doing that, you were only human, Rose, that was how you thought. You brought me back with the powers you had obtained- but because you were exactly that, you brought me back forever.
So, that's how it is. I can't die- we're still not sure about the aging thing, though. The Doctor had never encountered someone like me before. Heh. Guess who just got a little more unique.