Owls - Gil's world used owls for messages. And as he had to send a message to Gil's world to tell Strahan and Rabastan the bar was
safe to come back to, Asar-Suti needed an owl.
Obvious way to get an owl would be to catch one, would it?
If he wanted an owl, he'd best get one from the woods by the lake; and to catch an owl, the easiest way would be to be owl-shaped himself and catch a slightly smaller one. Eagle-shape would be frightfully unfair on the poor creature.
He stepped outside, disregarded the devastation in the garden for a moment, and shifted into owl-shape. Curiosity drew him to the big ship with the black sails and extensive damage for a moment;
there was somebody on it, too.
The owl peered curiously, but flew high overhead and straight into the woods on the other side; he could go and look at the ship another day.
In the woods, there were many creatures that hid, and it took him quite a while to find a small tawny owl that he could grab and drag off, protesting indignantly in owlish.
Asar-Suti flew right into the library window and there magicked the owl onto an empty book stand, and turned human shaped, which drew a new string of fierce invective from the bird. "What do you mean, can't deal with this?" Asar-Suti said. "The gods don't ask you if you can deal with life - the gods deal with you. My name is Asar-Suti, and you are going to be my messanger owl - and if you carry on like that, I will call you Fluffy. If you're good and do what I say, your name shall be Swift. Which shall it be? - I thought so."
He read large parts of a book on the training of magical messenger owls at Swift, hoping it would work. Swift didn't protest, but listened, head cocked attentively.
When Asar-Suti was sure the owl had understood what was expected of him, the god penned a missive.
My dear Strahan,
as was to be hoped, the world was saved at the last moment, last night.
Gil and I are not coming to the Wand World, and it is now safe for you and Mr. Lestrange to return.
- Asar-Suti
This he tied to Swift's leg; then he carried the owl dowstairs to send him on his way.
Asar-Suti opened the bar door, made sure he had the right world, and threw the owl out there.
"Shooooo!" he said, closed the door quickly, then went to the staff wing to find Gil.