Frustration

Frustration is a Normal-type charged attack. This attack is taught to all Shadow Pokémon by Team GO Rocket, but is replaced with Return upon purification.

Frustration is retained by Shadow Pokémon if evolved. Charged TM does not work on it. Shadow Pokémon cannot learn Community Day exclusive moves.

Trivia

 * On March, 2020, the global take-over mini-event, Charged TM could be used to change a Shadow Pokémon's Frustration to other Charged Attacks that that Pokémon could learn normally.
 * Shadow Pokémon can learn exclusive attacks in future events as long as they forget Frustration.