Mirage

The ability of Mirage pokemon changes depending on the opponent's type. 20% more attack against Dark. Gains 20% HP against Shiny. Copies the ability of Ghostly and Metallic pokemon when fighting against them. Onfacing Shadow pokemon, it transfers all its ailments to the opponent (If your pokemon is poisoned, it heals itself and poisons the opponent). And finally Mirage Pokemon lose 10% health against normal pokemon.