Besaid Island & Valefor

Only

Tidus washes ashore and meets Wakka.

HP: 750

Weakness: None

This is a tutorial duel. Just attack. If your HP gets low, use a Potion. He will yield after taking enough damage.

Later, inside the temple:

HP: N/A

Weakness: N/A

Yuna must defeat Valefor to earn its allegiance. Use Blizzard if you have it, otherwise standard attacks work.

Kilika Woods & Lord Ochu

Only

The woods are full of poison enemies. Bring Antidotes.

HP: 4,649

Weakness: Fire

This optional boss guards a chest. He can poison the whole party. Use Valefor's 'Sonic Wings' to delay his turn repeatedly. Use Fire magic.