Well, he's thinking, at least the Visser doesn't have the tail anymore. (This doesn't actually make it much harder to kill someone, and also the Visser didn't tend to kill people in a host anyway, waste of a perfectly good host, but still.)
"I don't know what happened to you," he says. "I am pretty sure Leareth did it, with his mind control, but apparently killing him either didn't work or didn't fix it, so there's probably nothing to be done. But this isn't you. You cared about our people. You understood that there were compromises we could not make, if we wanted to win. You understood that we were fighting xenocidal maniacs who have wiped out whole species just so they could inconvenience us, and you think they'll hesitate to wipe us out, once they're done? Maybe Leareth found one - or mind-controlled one - willing to say nice words about how Andalites and Yeerks can work together. But unless he can get them all, it'll never happen, and we'll lose everything, trying.
Orders weren't to kill you. For what that's worth. I want you back. We need you. I know who owns you now, and it's not us, but - if it were, you'd thank us."