"I don't understand what it'd be helpful with."

"The less it looks like we're hiding things, the better, and the less it looks like people here will listen to the Empire if it orders us to do things, the less likely it is to issue such an order and be embarrassed, though it may also cut our funding."

"Well, I don't know anything about any of that, but I'll talk to them."

And he is in fact the first to drop by their mansion in Vellumis; Marit is sleeping, not that Marit has told anyone he's sleeping, and will be a few hours. 

"Ah. Erm. Come...in?" The dragon does not look like he'd fit through the door to the mansion. "Or should the Legate come out..."

He can shapeshift human temporarily to go through the door, though with an expression of great annoyance, and he'll dragon again on the other side though there's only space for him if he's rather curled up. 

The legate, hearing the noise, comes out of his office, bowing, and descends stairs until he's at Parnoneryx' head level.  "How may I be permitted to address you?"

Gosh! Parnoneryx decides immediately that he actually likes Taldans. "You address the noble dragon Parnoneryx, hero of the Shining Crusade."

"Oh noble Parnoneryx, may I know what brought this Crusade to your attention?"

Preening. "My travels took me to this continent, and I learned of the great battle between Iomedae and Tar-Baphon, and she invited me to join in it, and see them to the victory that has eluded them for so long."

"May your strength carry them to it - Do I understand truly, that you joined solely for the righteousness of the cause?"

"I can name no cause as noble, nor any need as great, and no material reward could equal the knowledge that I played some great part in their triumph."

"No material reward? I am astounded by your generosity, surely it has no equal in all the world."

He preens some more. "Sometimes I am the most suited to hold those treasures captured from our enemies, but I assure you, that is not the concern which moves me; I hold them only for the greater benefit of the world."

"I beseech you, noble Parnoneryx, tell me of some of your great deeds in this Crusade, and some of those treasures you hold for the good of the world."

He'd be delighted. He's in fact only been with the Crusade these last few years, and is mostly in its service as a dragon, which is to say he flies around heartening the men and eating their enemies. ('Terrorizing' is usually one of the most important capacities of a dragon, but against the undead it's less relevant.) He has a sizable protective escort - he's not so ancient a dragon as to be nigh-invincible on a battlefield like these battlefields -

For the good of the world he holds a lot of nice custom magic items seized off Tar-Baphon and his lieutenants. It's not outrageous pay, for a dragon's aid, but it's not especially stingy.

Domnicus thanks Parnoneryx for his condescension, and offers him a small parting gift of gold as proper tribute for such a majestic individual.

Parnoneryx is delighted and leaves to tell Iomedae that he doesn't see why she's so worried, the Taldans are a lovely and civilized people. 

"Bad people can also employ flattery, though I make no claim the auditor is a bad person."

"Why would an enemy of our cause give me a present?"

"It is probably the recommended dragon procedure, and in some cases prevents the departing diplomat getting eaten."

"I wouldn't eat someone because they were rude to me!"

"I know. I have great faith in you. But the ways that humans usually convey to one another that they need not be afraid in another's presence don't come naturally to dragons, making it hard for humans to tell which dragons will eat them. - Marit, there you are. Go entertain our auditors."

"They're lovely! They give excellent presents!"

"...yes, sir," he says tiredly, and Teleports to Vellumis, and goes looking for the diplomatic residence.

The diplomatic residence is this door here, between these two other buildings. Someone greets him. "Can I take your name to the Legate?"