As the drink takes effect, those words make less and less sense. Lan Zhan outright frowns at him, accusing him without saying a single word. You are not an Emperor!

"Lan Zhan." his low voice sounds sluggish, "Courtesy name is Lan Wangji."

Then he heaves a tremendous sigh and picks up a cup of water, promptly trying to pour it over his head. For what purpose? Clearer thinking?