Soaring the Sky

This is a brand new feature where you can fly freely in the skies of Hoenn. This is not immediately available but you'll get to this point as you continue on with your adventure. You can only Soar by riding Latios or Latias and you need the Eon Flute to summon them. This will make them Mega-Evolve and give you a ride to the sky.

You have free control with the actual flight. You can view your location real-time using the world map displayed on the lower screen, you can perform tricks mid-air, and you can land almost anywhere. Soar will give you the freedom to explore Hoenn from a whole new different perspective.

While flying, you can encounter wild Pokemon and have an aerial battle. Surprisingly, you're not only limited to use flying Pokemon; you can use any Pokemon in your team to battle or capture the wild ones you encounter. Wild flying Pokemon fly together in flocks; approach them to trigger the encounter.

There very special locations called Mirage Spots where you can encounter rare Pokemon, valuable items, and even specific legendary Pokemon. It is said that you need certain requirements to access some of these Mirage Spots and trigger the encounters with the Legendary Pokemon residing within them.

Reference and Image Source: pokemonrubysapphire.com