Dark Cloud King's Curse Strategy
The boss of Sun & Moon Temple, King's Curse, is another really easy one of the game in my opinion. The strategy for him is really simple, what you'll want to do is switch to Ungaga each time he surrounds himself in the black smoke, the same material that makes up the impassable doors you need Ungaga for.
Once he throws this smoke up you want to use Ungaga's whirlwind attack to blow it away. The boss will be stunned after you do this too momentarily which is where you'll switch to Toan or some other damage dealer and run up and smack him! Depending on how strong your weapon is and if you use a Stamina potion or not, this boss will most likely take about 10 hits.
Semi important note: If you are about to fight this boss and haven't given Jibubu the Foundation you got from Queens you'll miss out on getting the Sun Gem in the next town! If you missed out on even getting the foundation, well you're just screwed then, sorry!