Greater Doomer is a giant indigo and purple Sphere Doomer with yellow eyes. It has 12 feathers hanging from the back of its jaw, one less than the Grand Doomer. Unlike other winged Doomers, its mouth does not hold anything.
Greater Doomer is first fought in the Ruins after its quest is unlocked for 16 Gem Apples. It is in the Tough boss category and must be defeated before the player can access Pyribbit in the Volcano. When Team Kirby enters its area, the boss emerges from a dimensional rift. It attacks primarily by swooping back and forth between the two edges of the screen, spitting orbs, and dropping orbs from the sky. When furious, it gains new attacks: It spits orbs from the background, rushes into the foreground, rockets across the screen, and pursues the Kirbys while creating explosions around its body.
Greater Doomer is later fought in the Dunes. Here it is in the Tougher boss category, and must be defeated before the player can access Landia EX in the Decisive Battlefield. Its new attacks include spitting orbs that hover in the air before launching toward Team Kirby; rocketing halfway across the screen, pausing to aim again, then rocketing all the way; and generating three blobs that revolve around its body.
Greater Doomer's model and animations are largely reused from Grand Doomer and Sphere Doomer from Kirby's Return to Dream Land. Some attacks are reused as well.