Shadow Tag is an Ability that prevents opponents from manually switching out or fleeing from battle unless the opponent also has Shadow Tag. Forced switches from moves such as Roar and U-turn will still switch out the Pokémon. A Pokémon holding a Shed Shell will be able to ignore this Ability's effects and switch out, while a Pokémon with Run Away or a Smoke Ball will still be able to flee.
The Shadow Tag Clause battle rule can prohibit Pokémon with Shadow Tag
|Pokémon||Type||Ability 1||Ability 2||Hidden Ability|
|Mega Gengar||Ghost||Poison||Shadow Tag||None||None|