Planetary Spirit Magic

Planetary Spirit Magic (惑星精神魔法) is a Holder Magic and a type of Spatial Magic used by Planetary Spirit Mages that involves the summoning of Planetary Spirits.

Description
Planetary Spirit Magic is a type of Magic in which the user summon Planetary Spirits by opening their gates through the use of Planetary Spirit Gate Keys. These keys are separated into three classes: the more common Lead Keys, the uncommon Bronze Keys, and the rare Platinum Keys. Keys for Planetary Spirits are counted in Units (collectively without regard of Lead, Bronze or Platinum), and a Planetary Spirit Mage is noted by how many Units they have obtained.

Contracts and Rules
When a Planetary Spirit Mage receives a Key and open its Planetary 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 it's contractor. This simple agreement leads to a dedicated and serious bond between the Spirit and summoner. However, under certain circumstances, i.e. during battle, and a Spirit is summoned for the first time, the making of a contract may be suspended on a later date. Contracts can be broken if the Mage gets arrested, leases the Spirit by themselves, or dies. When a Planetary Spirit Mage summons a Spirit, it appears directly next to them, as that's where the gates to Space have been opened. It's impossible to summon spirits elsewhere.

The Spirits must also abide by certain rules enforced by the Planetary Spirit Queen. 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 "force closed" in battle, which means they can be forced back into Space by the summoner's will, though not every Planetary Spirit Mage is capable of doing such.

Planetary Spirits also have different categories of sorts that fall under the basic summoning conditions from their owner. For example, Mars summons himself most of the time without Primrose Wisteria doing so herself; Ceres has also summoned herself various times, as have many of Spirits. Also, if the trust between the Planetary Spirit and the owner is not an issue, contracts can be temporarily dissolved. It also seems that if the Planetary Spirit is strong enough, they can employ their owner Magic to stay int he Human World, when/if the contract is not in action. Additionally, Planetary Spirits grow stronger if their summoner grows stronger in terms of Magic Power.

Spells and Abilities

 * Force Gate Closure (ゲート閉鎖を強制): Closing the gates requires a mutual agreement from both the summoner and the spirit. However, some Planetary Spirit Mages have demonstrated the ability to force the gates to close in battle, compelling the Spirits to return back to Space.
 * Multiple Summons (複数の召喚): Summoning more than one Planetary Spirit uses up a lot of the summoner's Magic ability which may even lead to their death. However, some Planetary Spirit Mages have shown the unique capability to summon multiple spirits at a time. If one is capable of this feat, it provides greater flexibility as he/she is able to combine the strength and abilities of their spirits for more powerful attacks. They can also use their own Magic in combination with another spirit to increase the power of an attack.
 * Self Summoning (自己召喚): On various occasions, some spirit have been shown to be able to summon themselves without the need of their owners. Notable spirits include Mars and Ceres.
 * Planetary Dress (プラネタリードレス): A Planetary Spirit Magic spell in which the user incorporates the power and Magic of the Planetary Spirit they summon into their body, which manifests itself in the form of a dress and a tattoo of the Spirit's planet symbol on their body.