This was done with no prior save.

Defeating the Boss without Passwords:

• Spam "Tornado" as soon as the Boss can be damaged. Keep using Chi-Potions and spam "Tornado" until the Boss is defeated.

Defeating the Boss with Passwords:

• Select Sokka before entering the Boss Area and use "Chain Attack" or preferably "Mass Scare" as soon as you can.
• "Mass Scare" dishonors a enemy instantly, "Chain Attack" however will knockback enemies before dishonoring.