Organization
There is very little known about the hierarchy of Dark Guilds. All Dark Guilds, like legal guilds, are run by their respective Guild Master. Dark Guilds have S-Class level Mages, but it is unknown if the Mages in question are called "S-Class Mages". In the Grimoire Heart Guild they have a Deputy Commander, or second in charge, of their guild.
Balam Alliance
The Balam Alliance (バラム同盟 Baramu Dōmei) is an alliance between three of the four most powerful Dark Guilds in the world. Despite being referred to as an alliance, the three guilds do not interact with each other at all, and their alliance is nothing more than a non-aggression pact. They control the underworld, and all Dark Guilds, with the exception of Raven Tail, are under the control of one of the three. At the moment, the alliance consists of only two guilds following the disbandment and dissolution of Oración Seis.
| Guild Name | Description | Guild Master | Status | Symbol |
| Oración Seis | An extremely powerful Dark Guild. They were one of the three major Dark Guilds of the Balam Alliance that dominates the world of Dark Guilds. They comprised the smallest guild ever shown, with only six true members. They made an attempt to seize Nirvana. They were defeated by the Light Team, and are now dissolved. | Brain | Dissolved |  |
| Grimoire Heart | One of the three major Dark Guilds and a member of the Balam Alliance. It is the strongest Dark Guild in existence. Its members reside in a very large airship that flies over the land. They were initially hunting down the keys to the seal which binds the legendary Dark Mage Zeref, but seem to have attained all of them now. They have successfully found out that Zeref is on Tenrou Island and arrived there to find and unseal him. Because Fairy Tail members were also on the island for their annual S-Class Wizard Promotion Trial, a war occurred between the two Guilds, Fairy Tail won. | Currently Vacant | Active |  |
| Tartaros | Nothing is known about the this guild, except for the fact that it is the third member of the Balam Alliance. | Unknown | Active | Unknow |
Other Dark Guilds
| Guild Name | Description | Guild Master | Status | Symbol |
| Eisenwald | A Dark Guild that operated under the Oración Seis. They were supposedly disbanded by the Magic Council, but continued taking assassination missions and other guild activities. Filled with spite for the Magic Council, they schemed a way to get revenge. Upon hearing of the infamous Magical flute, Lullaby, they planned to kill all of the Guild masters as the attended the regular meeting with Lullaby's mass murder Magic. Their plan was spoiled by Team Natsu however. | Unknown | Dissolved | Unknown |
| Naked Mummy | A small Dark Guild operating under Oración Seis that specializes in Guns Magic. All their members look like monkeys. | Unknown | Active |  |
| Death's Head Caucus | Another Dark Guild is known for being unmatched in its number of successful assassinations. The only known members, the team Trinity Raven, participated in Jellal Fernandes's Heaven's Game against the Fairy Tail members. The guild seems to be extremely powerful, as all three members shown were able to match or overpower S-Class level Mages such as Natsu Dragneel, Gray Fullbuster, and Juvia Lockser. And their leader, Ikaruga, held the upper hand against Erza Scarlet for the majority of their battle. | Unknown | Active |  |
| Dark Unicorn | Another Dark Guild under Oración Seis' control. Nothing is known about them except that they all wear similar uniforms. These uniforms look a bit like school uniforms and most of them are worn in a style that is reminiscent of a high school delinquent. They also style their hair in a way that looks like the horn of a unicorn. They seem to carry around weapons instead of using Magic. | Unknown | Unknown |  |
| Harpuia | A guild that was personally lead by Racer, one of the Oración Seis. Its members were all easily defeated by Natsu while he was hunting for Jellal. They all resembled pit crew workers since they carried tools and wore helmets. | Racer | Unknown |  |
| Ghoul Spirit | A guild aligned to the Oración Seis that was quickly destroyed by the Thunder God Tribe. No leader was made apparent. Their guild was located northwest of Shirotsume Town. | Unknown | Unknown | Unknown |
| Red Hood | A guild aligned to the Oración Seis that encountered Lyon, Sherry and Jura. They all wear red hoods, as the name suggests. Many members of that guild were seen wielding staffs. As seen most of the Mages of the guild are exceptionally good drawers and use Pict Magic like Reedus Jonah, but the difference is that they use it on paper and not in their bodies. Also they've been show to use an ability called Unison Pict which combines all of their drawings and summons together using everyone's Magic. Also another reason of using this Magic might be that some of the drawings are really strong and the users can't call them out single-handedly such as in the case of the wyvern they summoned. Even Jura Neekis admired their drawing skills and capabilities but nonetheless defeated the wyvern as well as all of them with minimal effort. | Unknown | Unknown | Unknown |
| Fairy Tail (Edolas) | Fairy Tail (Edolas) is an alternate universe counterpart of the Fairy Tail Guild from Earth Land. The Fairy Tail Guild was the only guild in the entire Edolas realm and was treated like a Dark Guild since Mage guilds are banned. It was therefore targeted by the Royal Army for destruction. Now that Mystogan sucked all the Magic of Edolas to Earth Land, it doesn't have any Magic anymore. | Unknown | Active |  |
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