Watching Return of the King, and Aragorn's "warcry" to call the beginning of the attack - a mere whisper of "For Frodo," reminds me of Captain America's call to arms during Avengers Endgame...
... so why is a whispered battle cry so effective at moving the audience? and are there any other examples?
I can only immediately think of one other, and it's not a call to arms for others, as much as reaffirming his own power in adversity: in "V for Vendetta," V whispers "...my turn" after absorbing a barrage of bullets, immediately before slaughtering his assailants.