Archives are the core of Magic within the world of Trinity Seven. This is by which a "Magus" draws power from. Upon choosing an Archive, a Theme belonging to said archive must be selected that will be the main focus of magical study for the magician or Magus.
In the Trinity Seven universe, magic is both an energy and an art form that magicians utilize to achieve the desired effect. However, all mages appear limited to studying one of seven respective Archives. Within each archive are many Thema, which it appears mages can study more liberally. There appear to be four Thema per Archive, making 28 in all, additionally, a mage is not limited to studying just one of them, but usually, picks one as his/her main. Each of these archives is centered around one of the Seven Deadly Sins, they are:
- Luxuria (Lust)
- Superbia (Pride)
- Acedia (Sloth)
- Ira (Wrath)
- Avaritia (Greed)
- Gula (Gluttony)
- Invidia (Envy)
Most magicians will choose an Archive and Thema that is opposite of what their personality is, as that appears to be the easiest for them to use since Magic is irrational by nature, in other words, they must think in a way contrary to themselves.
There are several magical armaments and tools that are available only to an individual who has mastered a Thema, for example, the Iscariot member Rogue has come to possess three such tools. Magic King Weapons also require their user to have mastered three Thema and become a Trinity.
Contrary to the norm, even for Magic Kings, Arata can use magic from other Archives despite being a member of the "Superbia" Archive himself by accomplishing three processes of analysis, basically, deconstructing other people's magic for his own use, Liese can also do this by stealing other people's magic directly.
At the time of the Great War, there were eight archives (Luxuria, Superbia, Acedia, Ira, Avaritia, Gula, Vainglory and Melancholy) But the master class Magus Kings of the extra 2 archives (Vanitas and Melancholia) used their last crest, which caused the disappearance of those 2 archives. Later on Invidia was discovered and now is one of the 7 Archives.