Here's when Yuna confronts the Emperor in Return of Darth Sidious.
[we return to the castle and then we see the Emperor as Yuna walks in]
Yuna: [stops in sternly]
Darth Sidious: Welcome, night filly. Don't you know who I am?
Yuna: I know who you are, you're Darth Sidious!
Darth Sidious: You don't seem afraid. Are you not surprised to see me?
Yuna: I'm not afraid of you. My mama told me all about you.
Darth Sidious: [evil laughs] Smart girl.
Yuna: What happened? Why did you turn bad? Let me help.
Darth Sidious: I don't need help from you!
Yuna: Please, the dark side isn't a good place to be!
Darth Sidious: Shut up, jerk! [slaps her]
Yuna: Ah! [flies back]
Darth Sidious: [sits in the throne] Strike me down, and your journey to the dark side will be complete!
Yuna: [activates her lightsaber]
Darth Sideous: [smiles]
Yuna: [charges but then another saber clashes with hers]
Princess Luna: [darker] Doing something?
Yuna: Mama! What are you doing?!
Princess Luna: [darker voiced] Stop calling me that!
Yuna: You are!
Princess Luna: [darker voice Royal Canter-lot] NO!!! IF YOU WANT TO GET TO SIDIOUS, THEN YOU'LL HAVE TO FACE ME IN A DUEL!!!
Yuna: Fine, but this'll hurt me, more than it will you.
[they clash their sabers at different angles]