Here is the quote of each character that I mentioned above will say when finally almost defeating Garrosh:
Thrall: you have failed me and your father Garrosh ! you are a disgrace to be among the Horde ! (Thrall unleashing earth fury power from his shamanistc power) THIS IS FOR CAIRNE !! DIE !!
Jaina: You will pay dearly for what have you done !! FOR THERAMORE !! (Jaina unleashing her ultimate arcane blast)
Baine: People like you have no place among us !! DIE in the name of my FATHER !!!
Varian: Finally..what I have been waiting for so long ( Varian charging Garrosh and ready to cleave him) JUSTICE WILL PREVAIL Glory to the alliance !!
Vol'jin: I told ya when tha time comes dat ya failure is complete and ya power is meaningless, I will be dere to end ya rule, swiftly and silently.
Saurfang: I told you I won't let you take us down that dark path again, young Hellscream. I'll kill you myself and THAT DAY IS NOW !!! (Saurfang using his mighty cleave)