How do I get down from here?

Just defeated Odin and caught Jirachi.
Still at the top, and I don't know how to get down.
Where do I go now?

You, unfortunately, have to walk the whole way down! It's a long trek, but there's no other way.

I figured that was the case, but the stairs kept pushing me up.
So I decided to ask here.

What do you mean the stairs keep pushing you up? Which stairs?

These stairs

For some reason, the double battle event didn't trigger for you. You were supposed to fight Thor and Loki before going to catch Jirachi.

From where you're standing in the picture, go left once, then up once, and press C.

I knew something was off when I didn't fight those two. Thanks!