That's nice, but he's going to refrain from celebrating until he can put out all the fires he already had.

What's the status of the preparations?

Behind schedule. A number of his subordinates are of the opinion that this is basically to be expected and his entire schedule was too ambitious to begin with.

It's a good thing he's in charge, then, and not them. The barbarians might not be in a hurry to storm his fortifications, not after what happened last time, but that isn't going to last. He's sitting in the heart of one of their cities with a hostile army; they certainly can't afford to leave him there. Even leaving aside the economic implications of losing what has got to be one of their biggest cities, they're sure to be furious about it, and the imperial performance hasn't been overwhelming enough to turn that into real fear. That means they need everyone deployed on a real defensive line, with their rear cleared enough that if they need to withdraw it can happen in good order without a rout, and to be frank they need it done yesterday. They can redirect some people from the looting to help get it done, painful as it'll be to miss out, and try and get things back on schedule. The dragon corps?

It hasn't spontaneously reconstituted itself, if that's what he means.

But he could maybe get one more deployment out of it, if he really had to, as long as he was willing to accept he wouldn't have a dragon corps afterwards.