Local Trainers Pokémon
After you learn of what you are to do, leave the Devon Corp. and Fly to Granite Cave.
Inside, head along the path north and west, then downstairs into the cave in which you met Steven long ago… As you approach, you’ll see Zinnia once again; how does she keep antipicating our movements? In any case, she apparently doesn’t mind handing over the Meteorite Shard .
She does however ask for a battle, and who are you, the Pokémon League Champion, to refuse an offer like that? Still, despite that, it could hardly be called a boss, given what the Elite Four were like. She even has an affinity for Dragon Pokémon, akin to Drake.
Afterwards, you’ll be given the Meteorite Shard. After a cryptic quote from Zinnia (referencing Pokémon Black/White at the same time), she’ll leave and you’ll get a phone call. Anyhow, leave the cave and head to Mossdeep.
Head to the Mossdeep Space Center at the northeast side of town at the very top. Inside, go northeast to the stairs and you’ll head on to 2F. There, Prof. Cozmo will explain the plan.
In essence, we are to use the Infinity Energy stored in the space centre’s rocket in combination with the life energy of humans found in Key Stones, to replicate and amplify the energy found in Mega Evolution.
The rocket will in turn use this massive energy to create a wormhole in space in the path of the asteroid, sending it off to some other part of the universe and making it E.T.’s problem.
However we’ll need a second Meteorite Shard and Zinnia has it. Luckily, she’ll come in and hand it over nicely. Not! She disagrees with the current plan and how it will unnecessarily repeat the sins of the past that this same technology created 3,000 years ago… or worse.
That said, no alternative currently presents itself, so there’s not much else you can do. The second Meteorite Shard we need will be found at Meteor Falls, and Steven will tag along with you on this one. So, then, Fly to Meteor Falls.
Enter the cavern. The path we discussed was in Meteor Falls in Full ; if you’ve not sidequested here yet, visit the A Final Detour chapter for the full details. It will be after the Old Couple, before ascending the many ledges, that you will meet up with Steven and find the Meteorite Shard.
He has gotten it from a descendant of the Draconid people, those tasked with passing down Mega Evolution’s skillset, who worshipped Rayquaza in the olden days, for Rayquaza has calmed the many catastrophes of the Hoenn region, be it meteors or the awakening of the Primal Pokémon.
It was the meetings with Rayquaza, when a sacred stone was in his presence, that triggered the world’s first Mega Evolution. The person who did this was known as the Lorekeeper, and they could summon Rayquaza at will. The current generation’s Lorekeeper … is Zinnia.
She joined Team Aqua/Magma in an attempt to summon Rayquaza to stop the meteorite by triggering the Primal Pokémon’s awakening and making him calm it. You unwittingly foiled her efforts, but she will continue this quest until it is completed or she dies trying, she is so convicted.
Anyhow, leave the cave and return to Rustboro.