>>53534334In the first MD games I believe she asks you to go save Latios (or it could be the other way around. It has been ages since I played it).
In Explorers, you can only encounter them in the Dark Crater as part of the regular spawns if you have the Mystery Part or Secret Slab in your inventory, and even then they have a very low base recruitment rate.
Not sure about Super but I’m playing the post-game now (which is the first time since its release in early 2016 that I’ve picked it up). Have yet to encounter them but I hope they have a unique mission similar to the one you get when you escort the Explorer’s Grovyle to the Shiny Celebi.