You have to go to the other alleyways around Peridot, Opal, Obsidia, Lapis, Coral ward, during day time I think, and it will be disguised as another pokemon. After a while it will battle you.
That's the point. You're supposed to train a variety of pokemon, not just one or two. My starter was always a couple of levels above the cap yet I managed by training other pokemon to rely on. The difficulty depends on the way you're playing.
The key is in a house in the park between Onyx and Obsidia ward, and they are locked up in a warehouse down south. And you're at the wrong shack, it's in the middle, there should be a trainer standing to the right of it.
There's a heart scale near the train in the Chysolia Forest (find the train yourself) and the gym leaders are far from impossible if you train more than one pokemon.I beat Serra using my Blaziken (bulk up, double kick/blaze kick) and my Gyarados and if they fainted I still have others to use.
This is still helpful thanks. Saves me from clicking on every single rock during the day.
Edit: Just when I was about to give up I caught a glimpse of it. xD
Once I've activated the event, does it have to be night time to search for it and does it hide in objects or does it just move to a different location?
Staircase: wasn't that the part where you had to find Victoria? Just go through the cave until you get to a part with unknowns.
Daycare: you only need 1 key, it opens all the warehouse doors in Coral ward.
Missing boy: it has to be windy I believe, check the entrance to the Obsida slums for flying hoppips.
Did you go talk to the mother at Lapis ward after rescuing him from the drifloon? He only appeared for me after I went to the mother then back to Jasper ward.