[How to go back?]

So I'm stuck against Terra, the ground gym leader... Is there a way for me to go back to Obsidia for some items? Because I can't seem to remember how

[Absol event vs non event?]

What's the point of getting absol from the waterfall when you can just get him from grass?

[Shiny Type: null]

So I want a shiny type null in the lab on 7th street and i managed to quick save while talking to the lady right before the type:null attacks her. So my question is when is it decided that the pokemon is shiny? If it's decided before i even talk to her, could you show me how to delete my last save.

Thanks

[I think I'm stuck help]

Don't know how to get out of here:

[Can't find move relearner house key]

Ok I got house key but when I try to enter the move relearner's house, it just says locked. I see "house key" in my bad too...

[Can't find move relearner house key]

I'm in railnet with both strength and rock smash and can't find it

[Looking for pachirisu]

So the pokemon that was bullied was zigzagoon which was a disappointment but I heard there's a chance of the pokemon running around the apartment could also be pachirisu but I never had the running pokemon in the apartment. Do I need to do something to trigger the pokemon to run? I have poke snacks and I have tried entering during different weathers but no use.