From Star Wars: Episode III - Revenge of the Sith
Be careful of the Jedi, Anakin. Only through me can you achieve a power greater than any Jedi. Learn to know the Dark Side of the Force and you will be able to save your wife from certain death.
What did you say? How do you know that...?
Use my knowledge, I beg you.
[igniting his lightsaber
] You're the Sith Lord!