Following the defeat (and preferably capture) of Primal Kyogre/Primal Groudon, their weather effect will suddenly evaporate as you flee the Cave of Origin, restoring calm, temperate weather to the Hoenn region and the world once more
After a heavily sentimental scene - we daresay one of the most so across all of the Pokémon core series - you’ll receive the Red Orb (in Omega Ruby) or Blue Orb (in Alpha Sapphire) so that you may make your newly-caught Primal abuse Primal Reversion to your will.
You’ll also receive the Eon Flute , which will allow you to ride on the back of Latios/Latias, soaring through the air. Latios/Latias doesn’t have to be in your party either. Now there’s quite a lot to soaring, so much that it has its own section, Soaring in Hoenn , so do check it out.
From this point, additional wild Pokémon - not normally native to Hoenn - will start appearing in old locations. To make them easier to find, speak to Professor Birch back in Littleroot Town to upgrade your Pokédex to the National Pokédex .
Anyhow. Go south to that grassy island, then east and south to find the Sablenite at the end of the path, which lets Sableye Mega Evolve if you want it to. Then head west from the island to the main city.
In any case, let’s make things easier by going to the Pokémon Center first. In the house far northernmost from there, you can have a number of Dragon Pokémon - such as Latios and Latias, among many others - learn Draco Meteor , a powerful Dragon move with a drawback.
In the house due east of the Center, you can speak wit the woman there for a Wailmer Doll for your Base. On the west side of town, in the house far to the north of the Mart, you can get TM31 (Brick Break), which teaches a good Fighting move.
Guess what’s left? Here’s a hint: it’s in the very center of town, and you should heal up before entering!