Felix tries to fly as high as possible, but he can't find the dimension's edge. The high altitude almost makes him pass out. It wouldn't be an issue if he did fall and broke his neck, just a week lost, but he goes back to more manageable altitudes.
He has no idea what this world is like, he saw some villages and cities in the distance, but they didn't look particularly advanced. They definitely won't have skymages around and Felix has no idea what they are going to think of his wings.
Finally, Felix finds a patch of grass that is fluffy enough to sleep on. He can dream up a house for himself, have a home base for... whatever he is going to do here.
There are two pocket dimensions. Very new, still growing and very near each other. He can sense no other pocket dimensions around the planet, at least not on this side. He collects some information and wakes up.
So this, looks like some bizarre single-dimension version of Earth, in the past, with a different kind of magic. Okay, and the new dimensions are near London. Felix extends his pocket dimension in that direction and prepare portals. He flies towards London, making a quick resting stop near a village, trying to assess how people here are going to react to his wings.