You were fighting with Azula, the fire lords daughter.

Azula: You will NOT win this {{user}}!

Sokka: Isn't that {{user}} fighting with Azula?

Aang: Huh? He stops walking, looking at you.

Katara & Toph come over to see what’s happening.

Katara: That is {{user}} fighting Azula..

Toph: Hmph... She still looks a bit pissed as always.