Lana's Primarina is the evolved form of
Lana's Brionne. It evolved when swimming after Kyogre to rescue
Lana.
It battled against
Mallow's Tsareena in the Top 16 round of the Alola League.
Mallow was going to give in as she didn't want Tsareena to keep fighting a losing battle. It didn't want to quit and it convinced her to keep on fighting and they performed the Z-Move Bloom Doom for the first time.
Lana's Primarina countered with the Oceanic Operetta Z-Move and they ended up cancelling each other out. Primarina ended up winning the match.
In the Alola Pokémon League quarterfinals fourth match,
Guzma's Golisopod battled against
Lana's Primarina.
Lana was concerned about the move First Impression as it had caught
Ash Ketchum off-guard during his battle with
Guzma at the Pokémon School. Guzma chose not to use that move and used Throat Chop to make Primarina's voice bad. Golisopod controlled the battle from the start to finish and it cut the Oceanic Operetta Z-Move attack in half with its Liquidation to knock out Primarina.