How do you get the dark side in Art 4?

When you reach Cloud Kingdom, hop across to the next platform where you’ll come across a circle with platforms with moons on it. Pound through the platforms until you find the right one for the Found With Dark Side Art 4 Power Moon.

How do you get to the darker side in Mario Odyssey?

In order to get to the Dark Side of the Moon, you’re going to need 250 Power Moons. Once you’re there, you’ll find yourself in a Moon area not unlike the one from the end of the game, only you’ll be surrounded by rabbits.