Saving the Spirit King

Saving the Spirit King is an anime-only event that takes place during the Eclipse Celestial Spirits arc.

Prologue
Having defeated Eclipse Ophiuchus and destroyed the Celestial Globe, the Fairy Tail Mages think that they've stopped Liberum, much to Lucy's concern as the spirit haven't returned to their normal forms. As Astral Spirytus starts breaking down, Horologium appears stating that they were too late to stop the ritual. He then begs them to come to his world to stop the King from erasing it.

Final Battle
The Mages land in a destructed Celestial Spirit World, and then watch as the planets get sucked by an anonymous stellar creature, who turns to be the Eclipse counterpart of the Celestial Spirit King, much to their astonishment. They notice 13 mini colored planets around the latter's head, containing the Eclipsed Celestial Spirits, as they attempt to rescue them, the king sucks all thirteen planets into his body, before he starts twitching. They then start attacking the latter, with their attacks turning useless against the mighty spirit. The king then waves his arms rapidly, thus overpowering the Mages. He then starts shooting red beams of light, turning everyone into start constellations upon contact, much to the others' shock. After only Team Natsu and Gajeel remain, Natsu, enraged, carries a celestial planet and throws it at Eclipse King, just to be destroyed by a single kick from the latter. As they re-assault, the Mages are puzzled as they see green black holes in the kings body, sucking everything near it. As Gajeel and Erza are unable to hurt the king indistinct body, Natsu tries to batter the king's head, just to before forced back by the latter's roar. Natsu, alongside his guildmates, are then caught in a green dark beam, identical to the own that drifted him during his early fight with Eclipse Leo.

The Fairy Tail members then lie down in front of the king's might. Fortunately, Natsy rises, stating that he caught Leo's scent in the King's roar, he then, by the use of Happy's Max Speed, flies rapidly through the king's roar, entering his body to save the Celestial Spirits who are still in him, leaving the outside for his comrades. Lucy, Erza, Gray and Gajeel entrust Natsu with the deed and charge once again at the Celestial Spirit Beast.

The Eclipse King starts shifting, gaining a new form, as Natsu and Happy fly in his body. As it it'd too dark to see, Natsu states that he can't locate the spirits, assuming that they may have been absorbed. Suddenly, a strong flash of light flashes, revealing an endless vast space ahead. The two are now lost, just for a group of meteors attacks them, in which Natsu destroys with his Fire Dragon's Wing Attack. They notice a shiny onject in the distance, where the scent in coming from. As they approach it, they are impeded yet again by electric bolts. Meanwhile outside, the Mages are continuing their attacks on the King, just to be outpowered again by the kings strong wave attacks, due to the energy rods of his back. Lucy then notices that the said creature seems to be in pain, in which they assume to be Natsu's effects. Their are proven correct as Natsu continue resisting the king's immune system, while the team manages to break his energy rods.

The King's attacks get weaker by the time and the team's attacks are finally working as they worry for their comrade's lateness. Meantime, the latter finds the core of the beast, with the normal Celestial Spirit King chained to it by 13 chains, representing the Zodiac Celestial Spirits. The spirits, in the chains, proclaim that it's for the Celestial Spirit King's sake. Natsu tells Happy to drop him down as he has decided to wake the king up. Currently, the Celestial Spirit Beast shifts forms again into a shape, similar to that of the original Celestial King. The rest decides to keep attacking, while Natsu starts absorbing the core's power, before devastating the whole essence, detonating the whole Eclipse King. After the explosion, Natsu and Happy are pulled out by Erza accompanying the Celestial Spirit King, turned back to normal.

Aftermath
With its king back to normal, the Celestial Spirit World returns to it's previous status, with those who where turned into constellations back to normal as well. The Zodiac Celestial Spirits then appear safely before the Mages, back into their original form, with them forgetting what had happened. The Celestial King appear, not remembering anything as well, thinking it was a pale dark dream that passes through him, yet thanking the Mages. Hisui then approaches the king, apologizing, in which he replies she need not to, before grinning at her. The celestial spirits once again present their keys to Lucy, much to her pleasure. The Mages then return to their homeworld, safe and sound, as there wasn't a time gap while the Celestial Spirit World was at havoc.