Analytic

 is a Pokémon ability introduced in the fifth generation. It boosts power when the Pokémon attacks last.

Description
When a Pokémon with Analytic attacks a Pokémon that has already acted, the power of the power is increased by 30%. This boost only activates if the opposing Pokémon used a move or switched from another  Pokémon. Mega Evolving, shifting in Triple/ Rotation battles and the charging phase of certain moves like Focus Punch do not count.

As a Hidden Ability

 * Magnemite
 * Magneton
 * Staryu
 * Starmie
 * Porygon
 * Porygon2
 * Magnezone
 * Porygon-Z
 * Patrat
 * Watchog
 * Elgyem
 * Beheeyem