He really hopes this works.

He waits until it's nearly upon him, holding his staff at the ready, then dodges out of the way, striking out and repeating the words, "I command you to return to your power confined! Fly!"

The beak of his staff hits the air and forms the glowing card that starts absorbing tendrils of magic off the bird, but it breaks away from it as it flies high up into the sky, before falling back down towards Theo.

"It's too fast! Try jumping on it when it attacks so you'll be able to stay close!"

Oookay.

Psyching himself up for it, he reminds himself: He's a Cardcaptor. He can do this.

He waits until the bird is nearly upon him, then smoothly side-steps and grabs hold of it in one fluid movement, looking a bit surprised.

The bird is likewise surprised, and tries shaking Theo off.

One of the Windies helps hold Theo up, however, and the other starts encircling Fly, extending its tendrils into magical ropes, trying to tie its wings close to its body so it can't take off.

"I command you to return to your power confined, FLY!" he shouts, swinging his staff against the bird.

It falls bodily onto the floor, unable to move its wings with Windy holding them. The staff hits a hard surface in the air before reaching the bird, and the glowing card appears there. The magic is drawn back into it, making the giant bird lose its shape and consistency until its been completely sealed back into its card form.

Theo falls a short distance to the ground when the bird disappears, but gets up pretty quickly, going over to grab the card, then says thanks to the Windies and wills them to disappear.

Walking a short distance so he's not in the middle of the street, he then proceeds to ask Cerberus, "Are they all going to be like that?"

"Like what?"

"'Like what'. Like what. You saw that bird, flying around in clear view of all those people! I didn't think they were going to be as obvious as that!"

He quickly focuses on his staff to shrink it into the Key, then puts it back into his bag.

"Fly isn't visible unless you have magical potential. Other people just felt strange winds."

"... And you didn't think to mention this earlier? Sure, not in the fight, but just before or something?"

He's pissed, even if it's pretty unfair, so he just starts walking without waiting for an answer.

Cerberus is carried along in the bag. "Sorry."

Well that's nice and all, but it doesn't help mitigate the panicking that he was doing in the fight.

"...this may be a good time to tell you that you'll need to eventually get the Clow Book from that museum."

Oh, might it.

"There's not some easier way to retrieve it? Like saying 'Clow Book, Clow Book, come to me' three times in a row? Maybe I'll also throw my staff into the air, and there will be some mysterious noise, and then everything fades to black, and suddenly: Clow Book! ... No?"

He might be venting. It's so hard to tell.

"No, it's protected against magic."

Cerberus can't tell.

"Oh, that's just perfect."

"... Actually, does that mean I can protect things against magic? Things like clothing?"

"Eventually."

Right. So nothing's easy, but things will get easier.

"Anything useful I can do in the short term?"

"Useful?"

"Magical...? Something that might help to protect me when this happens again? Or maybe something I should be doing to practice my magical abilities?"

“Well, now you can fly! And you can also meditate to learn more about your power.”

"Is Fly really docile enough to use? And if it is, and I can fly with it, does it have telekinesis or what? Why wasn't it flinging things around?"