If you have 3 Pokemon with full happiness that's what makes Nameless Cavern appear, but like I said for the other step, you have to wait almost a hole day the next day for the other one to show up, it happened with me, it's gonna happen with everyone. The almost a whole day thing is for all of the non uber legendary trios.

I found Mesprit like three days ago and i still haven't found the others yet.

Does that red X near Sootopalis City still show up? If not then you need to have 3 pokemon with full happiness, use Pokemon-Amie like on X & Y to check the happiness via choosing the switch option, that's where you check the happiness *I had to keep my Swampert, Latios, & Metagross in my party on OR for it to work as those are the 3 I had in OR that had the maximum happiness*. Also it'd be a good idea to get the National Dex from Birch *which, like I said, can be done right after dealing with Primal Groudon in OR or Primal Kyogre in AS*.

The red X still shows up but notning is in the giant ring.

It might be more complicated than that cause I haven't been using Poke amie at all but already have mespirit and azelf.

Does anyone want a HP Fire Protean Naive Froakie? I have an extra one if anyone wants it.

http://s20.postimg.org/ga6beasel/HNI_0039_JPG.jpg
Here's my updated secret base. I still need trainers...

Well, I can't think of a Pokemon to take on my Gaim-themed 1-on-1 Showdown team. Or any other rider. Anyone have any ideas?(I already have Gallade/Bravo and Swampert/Duke)

Either this is brilliant or the canon is really messed up.
Warning! Spoilers:
http://i2.kym-cdn.com/photos/images/...72/089/78d.png

Can't be canon. May being a big point to it for one.