Esuna spell - uses

[Odd]

Low level stuff? Useless. End game? Life saver.

Far from useless in low level stuff. Poison in both Brayflox and Toto-Rak come to mind. Yes they can be done without esuna, but esuna makes it easier, therefore useful. Also paralyze and heavy are a nuisance no matter what level you are. And besides, it's good practice for a healer CNJ to get used to using esuna, so they're ready come endgame.