Sceptile, Blaziken, Swampert: Given to you by Birch after you beat your father's gym.

Gardevoir: Given to you by Wally after beating him in Victory Road

Manectric: Located in New Mauville

Mawile: Found in Dewford Cave at the end of the bike puzzle

Aggron: Given to you by Steven after beating the Elite Four when you visit his home in Mossdeep

Medicham: Mt. Pyre (Ruby version)

Banette: My. Pyre (Sapphire version)

Absol: Hidden in the Cave of Origin after Kyogre/Groudon is captured or fainted