The boss shoots bouncing pellets in an arch rapidly. Each pellet deals a decent amount of damage, so it can be dangerous in a prolonged fight, as a lot of pellets exist at the same time. A melee character with a high DPS, such as a Boxer with a Mach Claw 5, is recommended to tear down the boss as fast as possible, but using a character to lure away the pellets also works. Thunder and Poison type weapons are best against this boss.
This boss might be a reference to the Superball element from the Powder Gameseries, seeing as the boss is pink and fires small, bouncing, pink balls.