Synchronize is a Pokémon ability. In battle, it gives the opposing Pokémon whatever Status Condition the opposing Pokémon just gave to your Pokémon.
Pokemon with the Synchronize nature:
Elgyem, Beeheyem, Abra, Kadabra, Akalazam, Natu,Xatu, Espeon,Umbreon, Ralts, Kirlia, Gardevoir,
Munna, Musharna, Mew
Synchronize also has an effect outside of battle. Outside of battle, it gives a 26% chance (30% total) for a wild Pokémon to receive the same nature as the one with Synchronize. This works on Wild Pokemon, Shop Pokemon eg Casino/Pvp etc, Fossils and Pokemon Box. For Legendary Pokemon the effects of the Synchronize ability are +36% (for a total of 40%)