Mega Sableye has been confirmed for Pokémon Omega Ruby and Alpha Sapphire. The Mega Stone to Mega Evolve Sableye will only be available in Omega Ruby and Alpha Sapphire.
When Sableye Mega Evolves all its energy is concentrated into the jewel on its chest, which grows in size and detaches from the Pokémon’s body. Mega Sableye uses the jewel to protect itself from oncoming attacks, which apparently hardens providing a huge defensive benefit during battle.
