Human Subordination Magic

Human Subordination Magic (人間隷属魔法 Ningen Reizoku Mahō), also called the Ruler's Magic, is a Lost Magic used by Zoldeo and, formerly, Capricorn.

Description
It allows the user to cast significant influence over humans, making it possible to make them subordinates for the user. In battle, it could be used to temporarily weaken the physical and Magical abilities of humans around him. With this Magic, Zoldeo was able to dominate a battle against four of Fairy Tail's Mages (two of them were S-Class candidates) all at once. However, the Magic does not work properly on non-humans, such as Celestial Spirits. It also allows the user to kidnap and summon humans to aid himself in battle, which means that, in terms of Caprico, it is essentially a reverse version of Celestial Spirit Magic. Humans summoned by the user materialize in a "dissolving" manner, and then disappears afterwards in a similar manner. And like spirits, summoned humans are sentient, albeit under the imperatives of the user, and can even verbally respond to commands, implying that it does not completely eliminate free will of the recipient. It can also act as a means of transportation, allowing him to recall his human guildmates for him to later release onto the battlefield.

Side Effects
This type of Magic also has weaknesses and unfortunate side effects. If this Magic is used to take control of anything else aside from a human, then it ends up permanently fusing the user with his target instead. This is how Zoldeo ends up possessing Caprico; though it seems that it is possible for the user to switch bodies with another non-human entity at a time. It also seems that his real body from this point onwards cannot manifest in the real world for more than a few seconds as after he was knocked out of Leo's body, he dissolved into the air.