Final Mova

Final Nova (決勝新星) is the combined form of Dark Oak, Black Narcissus and Pale Bay Leaf, with Dark Oak being the dominant mind, created through the Metarex's forestation process. This transformation comes in three forms, the two first which is the result of the form's metamorphosis, and the last which is a last-ditch effort for Dark Oak to claim victory.

History
It first appears to be a big three-headed snake-dragon planted in a planet that appears to be entirely composed off water that the Metarex created. It has all of the Chaos Emeralds in its possession, so it is very powerful. It attacks by wrapping itself and plantlike vines that it grows around the Blue Typhoon in order to break the bridge. In a final attempt to kill Sonic the Hedgehog, it swallows him alive and he is underneath the surface of the planet. The heroes managed to utilize the Master Emerald to fire a powerful laser via the Sonic Power Cannon, destroying two of its heads but it absorbs the power, growing more powerful from this. Final Nova appears to die when the water level of the planet rises and his final head is pulled under. It is then revealed that the planet has turned into a seed and makes a force field to keep Super Sonic and Super Shadow from destroying it.

It is finally defeated when Cosmo undergone a transformation, flies over to the Final Nova dissipating the gravitational field and plants herself on Dark Oak in the form of the seed, immobilizing it. Miles "Tails" Prower fired the Sonic Power Cannon loaded with Super Sonic and Super Shadow and killed Cosmo and Dark Oak, eliminating the Metarex once and for all.

Abilities and Powers
Final Nova possesses a variety of different powers in each of its forms, which are fueled by the Planet Eggs and the seven Chaos Emeralds, arguably making it the strongest entity in Sonic X. For each form it takes, Final Nova's power grows exponentially greater, eventually reaching the point where even two super transformed character are unable to defeat it alone and obtains abilities that are, in their own right, more devastating than the ones before.

First Form
In its first form, Final Nova is in the last stages of the Metarex's forestation project, and is extremely powerful from possessing the seven Chaos Emeralds. It can use its several roots as tendrils to attack enemies, either by extending them or growing them at an extraordinary rate. It can even grow roots from its neck and use them delicately enough to restrain smaller objects (in comparison to Final Nova).

Though its roots are fragile, Final Nova's main body possesses high physical endurance, being able to withstand being hit by several missiles, and easily brush off and repel Sonic his allies' attacks. Even after being hit with the full power of the Master Emerald through the Sonic Power Cannon and loosing two of its heads, Final Nova was still alive, another testament to the beast's high endurance. Beside endurance, Final Nova also has high physical strength, seeing as it is able to tear through the Blue Typhoon's interior and outer armor without effort, though it seemed to struggle against Shadow's level of raw strength.

Final Nova is capable of energy projection it this state and is able to fire laser beams from its mouths, much like Perfect Chaos, that is powerful enough to destroy one of the Blue Typhoon's engines with one shot. It also possesses hydrokinetic abilities, as seen when it is able to create water sprouts from its roots to catapult Sonic into its mouth, or when it rose the water level of the planet it was residing on to finish its metamorphosis. Final Nova is also able launch the fur on its necks as clusters of large, oversized needles.

Another ability Final Nova possess in its first form, is its ability to manipulate the minds, or more precisely the dreams, of those it has caught it its grasp, such as when it had caught Sonic and kept his mind trapped in a dreamscape while he was conscious and, at the same time, fight his attempts to resist.

Second Form
After absorbing all of the Chaos Energy from the Chaos Emeralds (merging with the Master Emerald's energy in the English dub), Final Nova was able to complete its metamorphosis and reach the final state of its forestation process, which was its second form. In this form, Final Nova's energy levels rises to high magnitudes so rapidly that they cannot be measured.

Final Nova can in this form release purple waves across the galaxy that, upon contact with plants, cause them to grow and flourish rapidly. When these waves come into contact with animals or even robots, however, they instead drain them of life energy, causing their victims to grow increasingly weaker, possibly to the point of death, in order to accelerate the development of vegetation. Animal/plant hybrids such as Cosmo are completely immune to these waves' effects.

When defending itself in this form, Final Nova can release dark energies from the holes in its shell to repel any attackers by pushing them away like a water current, and can even direct these energies' direction when released, allowing it to attack from any angle. It can also manipulate plants from a distance to act as its limbs, such as when it used the roots on the Blue Typhoon to keep Cosmo from getting the Chaos Emeralds to Eggman.

Even if an attack does get through, Final Nova possesses high physcial endurances as well, as seen when Sonic attacked it with a momentum-fueled Spin Dash, and was completely unfazed by it. Final Nova, however, was no match for Super Sonic and Super Shadow, who easily managed to tear Final Nova's second form apart.

Third Form
Final Nova's third and most dangerous form, is the core of its second form, which was exposed after its shell was torn off by Super Sonic and Super Shadow. In this form, Final Nova's energy levels increase to even higher levels than before and possesses gravity manipulating abilities, making it similar to that of a black hole.

In its third form, Final Nova can produce a powerful gravitational field, by compressing its Planet Egg's energy, that can almost completely immobilize Super Sonic and Super Shadow. At the same time, Final Nova can also turn its gravitational field onto itself, causing it to crush itself and its Planet Egg. If Final Nova's pressure should reach a certain point, it would cause Final Nova to implode and create an explosion that could destroy the universe. It was only until Final Nova was immobilized by Cosmo's transformation that the combined power from Super Sonic and Super Shadow in the Sonic Power Cannon was able to finally destroy Final Nova.

Trivia

 * Since the only body part Final Nova had below its throat was its roots, it is possible that it was talking by telepathy, as the vocal chords reach to about the collarbone in a normal animal. This would also explain why its mouth does not move when it speaks and why it talks to Sonic in his dream.
 * It appears to have fur while in its first form; however Vector refers to the Pale Bay Leaf head as 'a slippery one' while he and Espio are climbing on it.