That 'hopefully reappearing with Childermass' takes some time. Not terribly much, but the fact that the man chose to ride back to where they are rather than taking himself, an Arcanine, 9S, and a Mudbray through the shadows does drag that time out some. Even so their arrival isn't hard to spot thanks to the massive fire dog trotting on up alongside the little orange donkey 9S is riding. The massive fire dog who also can't see there's an illusion ahead, though familiar scents do cause him to slow to a stop. Considering Childermass is on his back, that probably makes sliding down off of him all the easier.

The Arcanine will start snuffling around the edges of the illusion just, but Childermass, unlike Baker, looks directly through the illusion. Well then. That's all something. The magician grabs the Arcanine by his ruff, pulling him into the illusion with them.

"What do you think you're doing? You broke one of the Prince's spells?!"

Yeah, rather than being helpful, he's here to tell them their utter morons.