An item to be held by a Pokémon. It boosts the power of moves, but at the cost of some HP on each hit.
The Life Orb can be obtained by going threw Union Cave to a previously inaccessible area within the Ruins of Alph. Once in the Ruins of Alph, Enter the previously inaccessible ruin building and solve the word puzzle.
After solving the puzzle unown will disappear and you can then drop threw the floor where he previously stood.
Once in the basement you will find the Life Orb in a poke ball along the left side of the wall.