The bird sways appreciatively. 

After a couple songs, the bird attempts to twitter along to the chorus of the next one. (He's not actually very good at this, but manages a half-decent harmony by following her lead.) 

"Oh the alto part for that one goes like -" She sings it for him and then resumes on the soprano line.

He adjusts and follows along!

When this one is over, he goes back to listening. 

SINGINGGGG

Eventually, Ipaxalon takes flight and re-endragons. "That was delightful, thank you." 

"You're welcome!!" She bows.

Not long after, Ipaxalon bids farewell and promises to visit before the voyage is out.

"See you soon!"

One afternoon about four days later, Ipaxalon pops into existence a ways above the ship and glides down to say hello.

By that time it's in port in Amsterdam and Rebecca's not on that same vessel any longer.

Huh, they made better time than he expected. Ipaxalon inquires after her on the ship, first. Did she happen to leave a note there or in port?

Yes, there's a note for him giving the name of the ship to South Africa she's traveling with!

Excellent. Ipaxalon thanks the crew and looks for the ship in question, or for a winged magical girl in a frost-themed outfit. 

The ship has set sail already, girl and all.

Well, that's awkward.

Eh, he wanted to do some monster hunting anyway. He takes off along its probable route at a sedate thirty knots and looks for ships that match the description. He stays mostly near sea level, the better to bait out attacks, but occasionally flies higher to scan the horizon for sails.

There are plenty of boats in the sea, but before he finds Rebecca he finds a sea monster! It's smaller than the last one, about the size of a cow, but quite fearless nevertheless about trying to seep between his scales and lacerate his skin.

This world having exactly one kind of common monster makes it really easy to plan a counter. 

The spell fire shield is slightly misnamed; it also comes in cold-shield variant. In Ipaxalon's case, it roughly multiplies the power of his cold aura sixfold for anything attempting to strike or grapple him. Thinning out enough to get between his scales is not going to go well.

Only after he is wreathed in the opposite of fire does Ipaxalon deign to start ripping the monster apart. 

It is smart enough to try to go for a wing, while shaped sharp-like and with enough momentum that the strike will keep going even after that part of the monster is frozen.

Clever.

Ipaxalon has been practicing melee combat for centuries, and he's better at dodging than most dragons of any age. But these things are fast. If the monster is lucky, it might put a hole in his wing anyway. 

The monster is not lucky today. Ipaxalon performs an expert midair twist to pull his wing out of the path of the strike. The monster gets a blast of cold breath for its trouble. 

That takes off a layer of it and what's left tunnels out and retreats into the ocean.

Ipaxalon gleefully casts freedom of movement and gives chase! (He can hold his breath for many minutes at a time, but not indefinitely.) 

It falls fast but he dives faster and he can catch up to it!

Ipaxalon attempts to shred it into small bits and freeze the bits with his aura. 

Yeah that basically works if he's too cold for it to try to dig into his claw beds.