Gemini

Gemini (ジェミニ Jemini), "The Twins" (双子宮 Sōshikyū), or Gemi and Mini are Celestial Spirits that are one of the 12 Golden Zodiac Keys. They possess the ability to mimic the appearances and abilities of others. Their key is currently owned by Lucy Heartfilia.

Appearance
Gemini are two individual twins of a single Celestial Spirit. They are both small creatures with blue colored bodies and two antennae. They have small, black, beady eyes with white pupils. They both wear shorts, Mini wears orange shorts, and Gemi wears black ones. Gemi has a "^" shape for a mouth, while Mini has an "v" for a mouth. Gemi has a sash running from his left shoulder to the right side of his waist and Mini has a sash running from her right shoulder to the left side of her waist.

During the fight of Lucy against Flare Corona, Gemini appeared with a different outfit. They are now both wearing white belts.

Personality
Depending on the Mage they're contracted with, they undergo personality changes to reflect said Mage's personality. While under Angel, they were sadistic, cruel, and clearly enjoyed tormenting other people like she did. However, they had a change of heart when they heard Lucy's thoughts of compassion towards her spirits, as well as her principle of treating her spirits as equals. When Lucy was unable to use her Magic during the battle with Angel, they came to her and were willing to help, even though they betrayed their master.

Gemi and Mini are generally shown to be very joyful Spirits. While waiting for orders, they dance and make various poses. They don't seem to be very shy, as they have no problems with showing their breasts to their enemies (they had transformed into Lucy at the time, and were under a contract with Angel).

Oración Seis arc
Gemini first appears after the guild alliance leaves the Blue Pegasus' base. While posing as Ichiya, they reveal themselves after stabbing Jura before leaving with Angel. They are later summoned by Angel during the Oración Seis' skirmish with the Allied Forces and attack Lucy Heartfilia and Gray among the confusion.

They later pose as Gray and incapacitate Natsu by luring him onto a raft, bringing about his motion sickness. As Gemini is about to deal the finishing blow, Lucy interferes by summoning Sagittarius. They froze Happy when he tried to help Natsu. Gemini attempts to attack Lucy, but their attack is blocked by Hibiki. After retrieving information on Hibiki from Gray's memories, they assume Lucy's form and use Hibiki's weakness of women by exposing Lucy's breasts, much to the real Lucy's dismay.

Gemini, with Lucy's abilities, commands Sagittarius to attack Hibiki. Lucy forces Sagittarius's gate to close, only for Gemini to re-summon Sagittarius. When Lucy tries to force him back again, she is unable to do it since Gemini summoned him and only they can force close the gate. Angel appears and challenges Lucy to a duel.

Gemini is later summoned wielding Caelum, and then seduces and defeats Taurus. Then, they attack Lucy after she exhausts her Magic. As they are about to deliver the finishing blow, Gemini recalls Lucy's memories and cannot bring themselves to attack her after seeing Lucy's love for her Celestial Spirits. In her frustration, Angel banishes them back to the Spirit World.

Later, in Nirvana having arrived at the third Lacrima, Lucy reveals to Happy that she has no Magic Power left, but then she will not give up fighting until the very end. However, Gemini summons themselves in order to help her destroy the Lacrima. Taking Lucy's form again, they summon Taurus and have him smash the Lacrima simultaneously with Natsu, Gray, Ichiya, Wendy, and Erza. Afterwards, Angel is arrested, breaking her contracts with her spirits. Gemini, along with Scorpio and Aries, seek out Lucy and form contracts with her instead.

Edolas arc
When both Lucy Heartfilia and Lucy Ashley are in towels, Lucy uses Gemini to show three Lucys to Lucy Ashley. Natsu thinks of a quiz party game and Happy does a "Who is the real thing?" game. However, the three Lucys aren't happy at Natsu for this suggestion.

Gemini plays a large part in Lucy's plan to get information from King Faust. Since interrogating him wouldn't work, she hoped that Gemini would be able to transform into him and steal his thoughts. However, the group gets captured before the plan is put into action.

Key of the Starry Sky arc
Note: Events in this arc occur only in the anime and do not constitute canon material.

Grand Magic Games arc
Gemini celebrates Lucy and her friend's return from Tenrou Island when Virgo brings them to the Celestial Spirit World. During the celebration, Carla and Happy run into a mob of Nikora. Gemini explains that Nikora's are a very common type of Spirit in the Celestial Spirit World. After the celebration, Gemini sees Lucy and her friends off with the rest of Lucy's Celestial Spirits.

During Lucy's fight with Flare Corona, Lucy summons Gemini, and the twins appear without Lucy using their key, attacking Flare and cutting her hair at same time. Gemini transforms into Lucy, (albeit only dressed in a towel, which prompts the crowd and Vijeeter to fall in love with the view) and together they attempt to cast Urano Metria, to finish off Flare, though their attack is erased by Obra.

Later, on the night of the seventh of July, Gemini is summoned by the combined efforts of Lucy and Yukino alongside the other Ecliptic Zodiac for the purpose of sealing the Eclipse Gate; the Gate having opened to let a flight of Dragons move into and attack Crocus. Springing forward, Gemini pushes against the door with all of its might; the group eventually succeeds in sealing the Eclipse Gate.

Eclipse Celestial Spirits arc
Note: Events in this arc occur only in the anime and do not constitute canon material.

Magic and Abilities
Copy Magic: The Gemini twins have the ability to transform flawlessly into anyone that they have contact with. With this, Gemini is well suited for purposes like infiltration and information gathering/retrieval. Once transformed, they will gain the transformed person's knowledge, Magic and their recent thoughts (if not while they are thinking about them in real time). When they recall memories, they talk in a bullet style listing; the amount of information that they can access is, of course, limited to the knowledge that the genuine counterpart is actually aware of, and nothing more beyond that. However, Gemini can only hold the transformation for five minutes, and they must touch the person in order to transform. Gemini can only retain the capability to transform up to two people, and any more additional transformation requires them to erase the older one of the transformed forms. Also, Gemini's transformation is restrained depending on its owner. It can only transform into people with the same level or lower Magic Power as their owner. Anyone with a higher Magic Power than their owner will result in an incomplete transformation. Gemini can also transform themselves into a near target without touching, but this restrains the appearance of the clone to the appearance that it had last time they have contact.


 * Mimicking Ichiya: As Ichiya, Gemini can use Ichiya's Perfume Magic. They also said that he's thinking only about perverted things.
 * Mimicking Gray: As Gray, Gemini can use Ice-Make Magic with the same level of Gray's original Ice-Make Magic.
 * Mimicking Lucy: As Lucy, Gemini uses a whip as a weapon. They can even summon other Spirits, and control Spirits summoned by the original Lucy. Gemini can also distract male enemies with her attractive body. During the Grand Magic Games, Lucy combines her Magic Power with Gemini transformed into her and together they cast Urano Metria. However, the spell was cancelled by another Mage before its effects could be seen.

Levitation: Gemi and Mini can both walk on the ground and float in the air. This ability also allows Gemini to make strong and fast aerial attacks with an aura of Magic Power around them.

Immortality: As Celestial Spirits, Gemi and Mini cannot die, unless they are somehow forced to stay in the Human World.

Fairy Tail Gekitotsu! Kardia Daiseidou
Gemini appears as a support character for Angel in the DS Game Fairy Tail Gekitotsu! Kardia Daiseidou.

Trivia

 * Prior to their proper introduction in Chapter 133, they had already appeared on the cover of the chapter release twice, Chapter 98 and Chapter 122.
 * Interestingly, Gemini is the only Celestial Spirit shown to be able to summon other spirits.
 * In Chapter 165, when Lucy makes her contracts, Gemi and Mini have their sashes running from the same shoulder to their hips, but it is corrected in the next panel below.

Quotes

 * (To Angel about Lucy Heartfilia) "Her beautiful voice... Resounds... I can't do it. Lucy.. loves them from her heart. She loves us Spirits!"
 * (To Lucy Heartfilia) "Sometimes that feeling gives you power."