"Try the Change on me while I'm in there?"

"Yeah." She glows and—

—is now holding the Change.

"Maze, take me outside Sadde's door, release!"

Maze takes him there, hiding Sadde and everyone else from view.

Nothing else seems to happen.

Well, he gives it an extra minute or two just in case, but after that, he dispels it.

"Apparently I can't affect you from the outside."

She uses the Card again—

—and there, much more comfortable.

"That's a good sign. Okay. Uh, what else? Or is the plan kind of ready?"

"The Time is supposed to be very powerful. We should try the Windy; it's gentle, but it's one of the most powerful cards."

"Yeah, that's probably a good idea, but what should Windy do? She's a very physical Card."

"And I suppose if she can't get past the walls, that doesn't necessarily prove anything? Kero, what's our most powerful card besides Windy?"

"The Maze, and then the Storm."

"Right. So I'll try to use the Storm, and the Windy, and we'll see if either of them can affect you."

Nod.

"Maze, hide me from their magic, release!"

He is hidden in a non-Euclidean pocket dimension!

"Windy, appear inside the Maze and...blow around, release."

She is conjured and... fails to do anything.

He dispels her.

"Storm, make a storm inside the Maze, release."

She, too, is conjured and fails to do anything.

"Anything else we can usefully test?"

"Perhaps how strong Shield spells are against Cards?"

"Alright. Sadde, try penetrating my shield."

He casts one around himself. 

She glows, Change is now in her hand, she tries using it on Alistair to turn his hair pink, and it fails.

"Scott? Your turn."