Check your map for a small icon to the west that shows the location of a cat statue (there's a second one very close to the Mermaid spring you came through). Run to the statue and use your new Catwalk brush technique to climb to the top of the cliff. Once there, move forward and you will be attacked by a new enemy type, the Blue Cyclops. To fight the cyclops, simply jump at him and unload with Rosary attacks. Power Slashes will get blocked by the mask he wears, and using other brushstrokes seems to provoke the enemy into more aggressive tactics. Watch out if the Blue Cyclops takes off his mask as he enters a Chaos Mode. Just avoid him entirely and wait for the mask to go back on before attacking.
Talk to the Watcher on the ledge and he will tell you about the missing Whirlpool Galaxy. Talk to him at night and he asks for a shooting star. Use your Celestial Brush to paint a single dot in the sky, creating the shooting star and revealing the Whirlpool Galaxy. Follow the path to the north and the camera will swing up to highlight the Whirlpool Galaxy. While standing on the whirlpool stone tablet, use Galestorm brush strokes to spin the galaxy. It will take three Galestorms in all to open up the whirlpool in the ocean. Hop aboard Orca, he's found near the dock where you first found him, and ride him into the whirlpool to travel to the Dragon Palace.