BioOlympia is the Gym Leader of the Anistar Gym and she awards trainers that defeat her the Psychic Badge. She is a strong Psychic who can see the past and the future through the use of Future Sight.
Sheryl explained that Olympia learns about the future by being guided by the voice of the stars. The incident off the coast of Houen was also allowed he to predict the incident with Groudon and Kyogre beforehand. Even though the world suffered from abnormal weather, her prediction enabled people in the Kalos region to take all possible countermeasures, so nothing serious happened.
Olympia's Meowstic♂ is one of the two Meowstic that Olympia has as her main partners. It battled against Ash's Talonflame and Ash's Frogadier in a double battle gym fight. Its Ability is Prankster which allows it to preemptively activate supporting moves such as Light Screen. That's why it could protect the female before the attack from Ash and his Pokémon could hit.