It's a lot of input to pack away for someone as weary and confused as Ultra Magnus. Ships and his rank thereupon, the associated command structure, even some sort of time displacement… he shunts all of it to the side for now; there's a greater concern here to him. Especially if this Rodimus isn't lying and does truly know Magnus' secret.

"No," Magnus starts and tries to seize Rodimus by both shoulders with trembling, scarred hands, leaning down to stare him straight in the optics, yellow to blue. "No, you mustn't tell anyone!" There isn't enough left in him to lie that he is only as he seems; Rodimus is so certain and Magnus has never been a dab hand with dissembling. His voice turns thin and desperate as he adds, "Absolutely no-one can know!" It might filter to the wrong people. The sort of people who would use it against Optimus.