Instructions
During your first visit to the temple, use three Pokemon to solve the first puzzle. You need a blue Pokemon cloaked with the power of water; use Vaporeon. You also need Pokemon cloaked with the power of electricity, use yellow Voltron. Flareon is the red Pokemon cloaked with fire power and it is the third Pokemon needed for the first puzzle.
On your second trip to the temple, you need an infant Pokemon, a young Pokemon and an adult or mature Pokemon. All three must possess psychic abilities. Use Ralts as the infant, Kirlia as the young and Gardevoir as the mature Pokemon.
Defeat Gordor -- after solving the Pokemon puzzles in the Fiore temple -- to unlock the wild card Pokemon at the end of the game.
Wait for the ending credits to finish and look for the wild card Pokemon.