Celestial Spirit

 Celestial Spirits (星霊 Seirei) are magical beings from their own separate universe, the Celestial Spirit World. Mages, called Celestial Spirit mages, are able to summon spirits by opening their gates through the use of Keys. These Keys are separated into two classes: the more common Silver Keys and the rarer Gold Keys. Keys for Celestial Spirits are counted in Units (collectively without regard of Gold or Silver), and a Celestial Spirit Mage is noted by how many Units they have obtained. A third type of Key (Crystal) was later introduced. The spirits that are summoned via Crystal Keys are noted to surpass the power of Gold Key spirits on occasion.

All Celestial Spirits are named after a different astronomical constellation.

Contracts and Rules
When a Celestial Spirit Mage receives a Key and opens its Celestial Gate for the first time, they have to set up a contract with the respective spirit. This contract consists of asking the spirit which days it can be summoned by the Mage. This simple agreement, much to the shock of Natsu and Happy, forms a dedicated, serious bond between the Spirit and summoner. However, under certain circumstances, i.e. during battle, a contract can be asked to be completed later. Contracts can be broken if the Mage gets arrested, releases the spirit by him/her self, or dies. When a Celestial Spirit Mage summons a spirit, it appears directly next to them, as that's where the gates to the Spirit world had been opened. It's impossible to summon spirits elsewhere. The spirits must also abide by certain rules enforced by the Celestial Spirit King. The only rule that has been introduced in Fairy Tail so far is that a spirit may not directly or indirectly kill its summoner under any circumstances.

When the gates are closed, it is required from both the summoner and the spirit to agree upon the gate's closure. However, spirits can also be "forced closed" in battle, which means they can be forced back into the Celestial World by the summoner's will, though not every Celestial Spirit Mage is capable of doing that.

Celestial Spirits also have different categories of sorts, that fall under the basic summoning conditions from their owner. For example, Loke summons himself most of the time without Lucy doing so herself, Virgo also has summoned herself once, as have Gemini and Horologium and if trust between the Celestial Spirit and the Owner is not an issue, contracts can be temporarily dissolved. It also seems that if the Celestial Spirit is strong enough, they can use their own Magic to stay in the Human World, when/if the contract is not in action. The strength of the Celestial Spirits is affected by the Magical strength of their summoner as Lucy once said that her spirits could become even stronger than Natsu if she trained more.

Celestial World
All Celestial Spirits spend their time in the Celestial Spirit World when not called through by their summoners. Being in the World seems to have some sort of rejuvenating effect on the spirits, restoring their health after being in the human world which, over long periods of time, can potentially kill the spirit. The reverse is also possible: humans are unable to breathe in their World so after a period of time, albeit a much shorter one, they would die. Such an occurrence (a human entering the Celestial World) is a serious breach of contract. This rule, however, is not absolute, since Natsu survives an extremely brief period in the Celestial Spirit World when he catches hold of Virgo just as she transits through the spirit world to reappear elsewhere in the human world at Duke Everlue's command.

Draco
Draco is a kind and powerful celestial spirit who enforces that celestial spirits should have good owners, he takes the form of a purple haired young man with a white wing and a purple wing. He has the powers of a dragon, capable of using Dragonslayer Magic to it's full prowess. He uses " White Dragonslayer Magic" which allows him to turn his body into light, and manipulate it.

Summoner-Rafiel Heartfilia

Lupus
Lupus is a noisy and upbeat spirit which takes the form of a young girl with long white hair, and uses a sword in battle, and has two white wolves accompanying her, she orders these wolves in battle. These wolves are capable of using powerful Ice magic in battle, and are able to physically fight as well. Lupus herself also is able to fight with a sword, using her nimble figure to get the advantage over opponents.

Summoner-Rafiel Heartfilia

Ara
Ara is a purple skinned and blonde woman with a black lond dress. She has the power to create chains and to cure other people when they feel pain. Ara is selfish and very greed, and can only be summoned in night places.

Summoner-Mirio Tachibana

Ophiucus
Ophiucus has a magic called Serpent Magic, which allows her to manipulate the snake, called Wife, to an unlimited degree like growing the size, duplicate and also producing a deadly venom with corrosive property. Ophiucus is agressive, but respect Mirio, and can be summoned when Mirio is fighting.

Summoner-Mirio Tachibana

Eridanus
Uses water and ice magic freely, can fly with her wings at a jet speed. She also owners a whip: "Fleuve d'étoiles" or the River of Stars. It's a whip that has the rope section made of water, with stars of different sizes flowing and/or floating around it, and all the "rope" is extending. Eridanus is really authoritarian, angry and bossy, and can only be invoked when near water or in high humidity environments.

Summoner-Mirio Tachibana

Carina
Carina can create and control resistent wood, and even alter the emotions of other people. Carina cries a lot, and is a frustate lover, and can be summoned at any instance.

Summoner-Mirio Tachibana

Lepus
Lepus uses Super Speed and High Jump,allowing her to run quickly&jump at high places.She can be both cheerful,playful and hyper or shy and polite.

Summoner- Nuryn Kuroki

Leo Minor
Leo Minor has a very negative personality,although he has shown feelings for his owner Nuryn.

Summoner- Nuryn Kuroki