Pao Archipelago

I only played through the game using magic. At first, I failed against the purple faction, then I defeated the Necropolis (orange), and finally the brown faction. I lost my own castle, but it was after I defeated the purple and orange factions. Luckily, there was a mentor in the Dungeon. I spent a long time taking out the orange faction's outpost.
The main thing is to go up towards the ship at the beginning and get the Phoenix Cloak (at the start) and the Book of Darkness during the game.