the drowning tag is now applied and removable to any guy the stat effect can effect, (so long as they start battle without the water breathing effect active they'll get the drowning effect.) so i think it is now functioning properly as drowning matches the mystery damage i could not figure out before
now for some bug reporting
1. small typo when olive trains with Apollo where it say nothing instead of noticing
2.the new interactable boxes linked to the carps ask if you want to steal, but skips the choice and auto steals