People won’t know where the message comes from, they’ll just hear your voice as though you were standing next to them. Everyone hears it at the same time. The message is not translated into anyone’s native language, everyone hears it exactly as you say it. The maximum length is 6 of your breaths.
‘Thank you for your obedience in making us rich and your world warm for us. We have no further use for you, so now we, the Reptilians, will take our rightful place as masters of this planet.’