"It's taken me all this time to realise that the Laws of Time are mine, and THEY WILL OBEY ME!" Best. Quote. Ever! And you're right, candy, there was something very Master-ish about him when he went all Time Lord Victorious.
I think that's why i love the character of the Doctor: the fact that one moment, he can appear to be a clear cut hero, and the next, you're reminded of what he really is: a renegade. Someone who went on the run from his own people just because he was bored. To be honest, without the Time Lords, it's easy to see from this episode and the classic series how inevitable it was for him to go power crazy without the Time Lords to stop him. In those final ten minutes, the Doctor was far more scarier than the Flood. Absolutely brilliant!
And that trailer was fucking awesome!
"My name...is the Master!"
I'm just a little more wary about Donna returning, tbh. Don't get me wrong - out of all four of the new series, she's easily my favourite companion - but that's why i'm wary. She was given such an emotional and brilliant exit. Like Rose did in Doomsday. Before RTD ruined it with Journey's End. As much as I loved that episode - with its awesome mega crossoverness - Rose's return is really the main thing that annoys me. So i hope that, when Donna returns, she's given a much better comeback than Rose got!