He offers a sad sort of smirk. "They're called the Daleks. And they are. Mutants in a tank. They've had all emotion removed except for hate. And they destroy anything that's not like them. My people, the Time Lords, fought them because they had learned how to time travel. Their plan was to destroy my entire universe, then break down the barriers between other universes until they destroyed the whole of creation."

His expression morphs to anger the more he talks. But he stops there, because well, this is why he had originally come back: to drink himself into oblivion and forget about what he did during the Time War.