Grimoire Heart

Grimoire Heart Guild is one of the three Dark Guilds that is apart of the Balam Alliance, they are very interested in releasing Zeref. Currently, in the S-Class Trial Arc, they have detected Zeref's magic and are presumably going towards Tenrou Island, on an Airship.

Location and Buildings
Grimoire Heart doesn't have any (or rather it wasn't shown) stable localization. They probably live and travel on a giant airship.

Strength
As a member of Balam Alliance, Grimoire Heart is probably very powerful guild with very talented mages. Example could be Urtear, who was chosen for member of Magic Council and even was strong enough to destroy it and fool Jellal Fernandes, one of the Ten Wizard Saints.

History
Currently the history of the guild and how it was created is unknown.

Guild Master

 * Hades

Other

 * Ultear
 * Mest?
 * Zancrow
 * Caprico
 * Rustyrose
 * Kain Hikaru
 * Meldy

Trivia

 * Grimoire is a textbook of magic.