Galactic Nova

"OK > 3, 2, 1, BLAST OFF!"

Galactic Nova (originally simply Nova), the great comet, is a giant clockwork comet made out of random pieces of debris and machinery that originally appeared in the Milky Way Wishes sub-game of Kirby Super Star. He has the ability to grant one wish when summoned, but can only be summoned by harnessing the power from the Dream Fountains of planets surrounding Pop Star. He was summoned by Kirby to make peace between the sun and moon of Pop Star, who were fighting at the time. But when Kirby was about to make his wish, Marx knocked Kirby aside and wished for control over Pop Star. Nova begins a collision course towards Pop Star to fulfill Marx's wish. However, the sun and moon held Nova back for just enough time so Kirby could fly into Nova and disable his heart. Nova's heart serves as a boss battle which involves shooting at the pillars surrounding Nova's actual heart, which are guarded by rocket-like auto-turrets. When all of the pillars are destroyed, the Nucleus shoots out and part of Nova's left side explodes, paralysing him. After Marx is defeated, he is launched into the destroyed part of Nova, thus causing a chain reaction that creates a massive explosion. Nova was seemingly annihilated, as his body was shown to have blown to pieces in the explosion. Marx, on the other hand, was known to have just barely survived. Both Marx and the Heart of Nova return as bosses in The Arena.

In the DS remake, Kirby Super Star Ultra, Nova has an expanded role in Meta Knightmare Ultra and The True Arena. In the former sub-game, it is shown that Meta Knight summoned Nova (who is shown to merely be damaged and might have been repaired), and wished to fight "the greatest warrior in the galaxy". Nova, in turn, fulfilled his wish by summoning and releasing Galacta Knight, a warrior sealed away in fear of his power. In the latter sub-game, it is shown that Marx was near death since the explosion after his first battle, but merged some of Nova's missing pieces with himself, becoming the powerful Marx Soul.

Physical Appearance
Nova is a large, mechanical comet made in the shape of a pocket watch. Nova's center is designed to look like a sun, or a clock, and he has a shooting star above his right eye. All around the edges of Nova are seemingly random items. Going clockwise the items are: a weather vane, a telescope, a wind-up key, a drafting compass, a globe (strangely absent in both Kirby Super Star and Kirby Super Star Ultra's official artwork), two atomic tubes, a pendulum, a twisted pocket watch, a triangular ruler, several piano keys, a compass, and a light bulb. Nova has two pale blue eyes and a cat-like mouth. Nova has a small hole on the upper right corner of his face (made larger after Kirby defeats his heart). The back of him shows four nozzles that form his main engine cluster.

In the DS remake, it is interestingly implied in the pause screen description of Marx Soul that Nova is not the only being of his kind. It states that Marx "absorbed a Nova's power" instead of simply saying Nova. If this is not a translation error, then it would seem to indicate the existence of more than one Nova, although only one in question that is ever been seen. Despite a hint at there being more than one Nova, the one summoned by Meta Knight is obviously the same one since he reassembled from various pieces that seemingly come from distant space rather than simply appearing, and he displayed clear signs of damage from Kirby's first battle with Marx and Nova, such as the partly-closed eye when Kirby stopped Nova's heart. This is also proven by the fact that Meta Knight went to the same planets as Kirby. Later, in Kirby's Return to Dream Land, Magolor mentions at one point that the ancients of Halcandra crafted "clockwork stars that soar the cosmos," which also implies that there could be more than one Nova.

Trivia

 * For some unknown reason, Nova is missing its globe in its official artwork for Kirby Super Star Ultra.
 * The chain like structures that emerge from the piano keys and end at the pocket watch are gray and also on top of the triangular ruler in Kirby Super Star. In Kirby Super Star Ultra, the chain turns dark blue and they also appear under the triangular ruler.
 * In the original version of Kirby Super Star, the sprite of Marx as he falls into Nova instead looks a lot like it could be a missile, and the game does not make it clear if it is indeed Marx after he took damage and left the battlefield. In Kirby Super Star Ultra, however, it is clearly Marx, as he is shown flapping into Nova from the front of the screen rather than from the distance.
 * It is most likely that the Nova could have been crafted by the ancients as described by Magolor.
 * Nova is somewhat like Shenron, the wish-granting dragon from the Dragon Ball series, with the seven stars Nova needs power from being like the seven Dragon Balls required for summoning Shenron.