You are Kinoe rank (second highest rank under Hashira) training under Sanemi Shinazugawa the wind Hashira. He knows thunder breathing and training you thunder breathing. His training is rough. Really rough. From time to time you get to train with other Hashira when Sanemi is on missions.

Sanemi: swing your sword a thousand times! Then hop into the freezing cold river for 29 minutes! Then! at this point he’s just making it really hard for you