Good job, I like it when people are able to ad-lib without sounding out of character or slipping from the voice they are using. With the second line, would you be willing to try again and put some fury behind the voice, in the particular scene this comes from, Celestia is not just angry she is going full out super-nova on the mare that ignited her wrath, or put it another way, she's acting like a momma bear between her cub (Twilight Sparkle) and an immediate threat (the mare). and finally as they say in theatre circles, break a leg.