If you think a 3 minute speech is the longest, clearly somebody hasn’t ran Tempest Keep a lot.
Ran that place over 600 times (combined across all of my toons), and he (Kael’thas) gives a 5 minute speech at the beginning, then you have to wait 2 min. after the first phase, and then right before the last phase, it’s 3 min. of speech again, and then finally after you kill him, he’ll “act like he’s dying” for about 30 seconds.