Before the pond exploded.
After jumping into the pond Raya began to cast her fire magic, this was something she had learned about while training with her master. While training with her master Raya had a situation where her master had ordered her to fight water mages, during this fight Raya ended up losing despite never losing to someone of the same stage before. This experience taught her that an opponent with the countering element of yours is much harder to face in comparison to other opponents.
Once learning of this weakness Raya began to search for a way in which to lessen this weakness's effects, and after trying multiple different things such as alchemy potions and using enhanced weapons, she eventually learned that the best way to counter this weakness was simply to train against it continuously.
'I'm glad I found this pond. Not only can I keep training here, I also don't have to deal with the constant nagging of those guards that master sent.'