Eclair

Éclairisse is a character of the day who appeared in A Campus Reunion!. She is a researcher at a Kalos academy specializing in Electric-type Pokémon and was Clemont's teacher in his youth when he studied at the said academy.

Éclairisse was surprised to see Clemont again and invited him and his friends to tour the local academy. After that, Éclairisse told the group more about Clemont's time at the academy, remarking that he was a brilliant student.

The town's electrical supply came under attack from Team Rocket, so Éclairisse and the group rushed to investigate the blackouts. She stood on standby while Ash and Clemont battled the Rocket trio. The next day, she was present when Clemont caught Luxio.

(Source: Bulbapedia)