Plerophory: full confidence; total assurance.
With a plerophory of assurance, each of the Avengers spoke into some imaginary, unseen, perfectly clear audio communications system. I mean, seriously, how were they able to seamlessly communicate with each other in the middle of all that mayhem. Oh well. Can’t wait for part two!
From Greek πληροφορια (fullness of assurance, to satisfy fully). From Greek πλήρης (pleres): full and φέρω (phérō): I carry.