Celestial Spirits are magical beings from their own separate universe, the Celestial Spirit World. Some wizards, called Celestial Spirit Wizards due to their specialization in Celestial Spirit Magic, are able to summon spirits by opening their gates via the use of Celestial Spirit Gate Keys. These keys are separated into two main classes: the more common Silver Keys and the extremely rare Gold Keys. They are also divided into the third class of the lesser known extremely rare Black Keys. Keys for Celestial Spirits are counted in Units (collectively without regard of Gold, Black or Silver), and a Celestial Spirit Mage is noted by how many Units they have obtained. All Celestial Spirits are each named after a different astronomical constellation. Out of the 12 Gold Keys, 10 are owned by Lucy Heartfilia and the remaining two are owned by Yukino Aguria who also holds the "13 Gate Of The Zodiac". Out of the 12 Black Keys, 11 are owned by Lena Heartfilia and the last one is owned by Victoria Bellavor.
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 and 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 is arrested, releases the Spirit by him/herself, 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 have 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, which fall under the basic summoning conditions from their owner. For example, Loke, Virgo, Horologium and Capricorn have all been known to summon themselves 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 or if the contract is not in action. The strength of the Celestial Spirits is affected by the Magical strength of their summoner.
When a Contract is not being acted upon, the Celestial Spirits remain in their own seperate dimension called the Celestial Spirit World. There are two of these worlds and they have remained seperate in their own rights, however it has been noted that it is possible for any Celestial Spirit to travel between both spirit worlds at his or her will without any restriction or harm.
Unknown GatesThe Celestial Spirit King - He rules all of the Celestial Spirit World and enforces the rules among all the Spirits. He has the power to stop time in the Human World.
Golden (Zodiac) Gates
Aquarius - Summoner: Layla Heartfilia(formerly), Lucy Heartfilia - "The Water Bearer" Aquarius is a mermaid equipped with an urn. She is one of Lucy's strongest spirits and is her most vicious.
Aries - Summoner: Karen Lilica(formerly), Angel(formerly), Lucy Heartfilia - "The Ram" Aries is a timid female with horns at the top of her head much like a ram. She has white and fluffy clothes, like a sheep. Her Magic utilizes wool abilities to relax her opponents, rendering them incapable of fighting back.
Cancer - Summoner: Layla Heartfilia(formerly), Lucy Heartfilia- "The Giant Crab" Cancer has a crab-claw hairstyle with six crab legs protruding from his back. He wields a pair of scissors that he uses for attacking and haircuts.
Capricorn - Summoner: Layla Heartfilia(formerly), Zoldeo(formerly), Lucy Heartfilia - "The Goat" Capricorn is a humanoid goat who was possessed by his former master through the use of Lost Magic. After being set free, he joins Lucy as one of her Spirits.
Gemini - Summoner: Angel(formerly), Lucy Heartfilia- "The Twins" "Gemi" and "Mini" are two miniature Spirits that wear sashes across their torsos. They can flawlessly transform and replicate into anyone they touch, acquiring their thoughts and Magic.
Leo - Summoner: Karen Lilica(formerly), Lucy Heartfilia - "The Lion" Leo appears as a man in a designer suit with his hair in the form of a lion's mane. He uses the Magic Regulus for combat. Lena considers him her most powerful spirit
Libra - Summoner: Yukino Aguria- "The Heavenly Scales" Libra is a young woman in an exotic dancer's outfit who hides her face behind a veil and is equipped with half of a set of balancing scales on each hand. Libra uses Gravity Change to alter her opponents weight.
Orphichus - Summoner: Yukino Aguria - "The Snake Bearer" Ophiuchus is an enormous serpent with a metal-lined jaw. He uses Poison Magic.
Pieces - Summoner: Yukino Aguria - "The Paired Fish" Pisces consists of a pair of enormous fish, one black and one white. Their true forms are that of a beautiful woman with black hair and fair skin and her son, a young man with dark skin and wild-looking white hair who wields a trident. They are both powerful fighters, but revert to their fish forms upon contact with water.
Scorpio - Summoner: Angel(formerly), Lucy Heartfilia - "The Scorpion" Scorpio is a rough man with a large gun, which is reminiscent of a scorpion stinger. Scorpio uses Sand Magic, which he casts by blasting great amounts of sand from his stinger.
Taurus - Summoner: Lucy Heartfilia- "The Golden Bull" Taurus is a minotaur with black and white splotched skin and dons a nose ring, a black speedo and a gray belt. He wields a giant labrys.
Saggittarius - Summoner: Lucy Heartfilia- "The Archer" Sagittarius is a man wearing a horse costume with a great skill in archery.
Virgo - Summoner: Duke Everlue(formerly), Lucy Heartfilia- "The Maiden" Virgo sports a black and white maid outfit, with chained shackles around her wrist. She has the ability to dig holes underground. She uses Earth Magic.
Caelum - Summoner: Angel(formerly), Will Neville's Disciples(formerly), Katja(formerly), Lena Heartfilia. - "The Chisel" Caelum appears as more of an item than a being which takes three different forms to attack.
Crux - Summoner: Lucy Heartfilia - "The Southern Cross" Crux is a human like cross, with a mustache and cross shaped nose. Crux has a lot of information about all Celestial Spirits and their masters, either in the present or in the past.
Horologium - Summoner: Lucy Heartfilia - "The Pendulum Clock" Horologium is a large grandfather clock. Horologium has combat and non-combat uses.
Lyra - Summoner: Lucy Heartfilia - "The Lyre" Lyra wears a bonnet and dress. She also has wings on her back, she has the ability to sing beautiful songs, she mostly sings about emotions, but she does take requests.
Nikora - Summoner: Katja(formerly), Lucy Heartfilia, Lena Heartfilia- "The Little Dog" Nikoras come in various colors, accessories and markings, Nikora takes up hardly any Magic power when summoned. So far only two Nikoras are currently contracted to a Celestial Wizard: Bella under the ownership of Lena Heartfilia and PLue under the ownership of Lucy Heartfilia.
Pyxis - Summoner: Lucy Heartfilia- "The Compass" Pyxis looks like a penguin with a big round face. It has a compass on top of its head.
Black (Forbidden) Gates*Vulpecula - Summoner: Lena Heartfilia "The Fox" Vulpecula is a slim young red haired girl with large brown eyes and a large red bow in her hair. She uses Illusion Magic.
*Draco - Summoner: Lena Heartfilia "The Dragon" is a muscular young man who can use magic to grow a pair of black dragon wings, horns, a tail and nails. He uses Transformation Magic and Fire Magic. Lena thinks of him as one of her more powerful spirits.
*Leo Minor - Summoner: Victoria Bellavor "The Lion Cub" is a seventeen year old girl with orange hair. She uses Celestial Spirit Magic and Preacipua for combat.
*Andromeda - Summoner: Lena Heartfilia "The Chained Princess" is a slim young women with purple hair. She uses Chain Magic.
*Lupus - Summoner: Lena Heartfilia "The Wolf" is a large wolf whose fur is reminescent of shadow or dark mist and who has red eyes. He uses Shadow Magic and Darkness Magic.
*Lepus - Summoner: Lena Heartfilia "The Hare" is a small black haired child wearing a white rabbit fur coat and hat with rabbit ears. She uses Snow Magic.
*Auriga - Summoner: Lena Heartfilia "The Charioteer" is a young man in knight's uniform with brown hair who often carries a bow staff. He uses Requip Magic and Sword Magic.
*Equeeleus - Summoner: Lena Heartfilia"The Foal" takes the form of a large well muscled black horse with red markings and misty black mane and tail. He uses Time Slowing Magic.
*Antlia - Summoner: Lena Heartfilia "The Northern Wind" takes the form of a young girl with stark white hair wearing an elegant kimono and bearing a pair of twin golden fans. She uses the fans to cast her Wind Magic.
*Apus - Summoner: Lena Heartfilia "The Bird Of Paradise" is a large pale green bird with darker green highlighting feathers and royal purple feathers along the crest on his head. The feathers on his face seem to be trimmed in gold-yellow and have the slight appearance of a crown, with a small red feather acting as a jewel. He uses Feather Magic.
*Cetus - Summoner: Lena Heartfilia "The Sea Serpent" is a large creature that seems to be a combination of a dragon and a snake. He uses Telepathy to speak and his sheer size as well as physical strength. Cetus can only be summoned from some sort of body of water!!!!