Void Magic is a very powerful lost magical element branch. It is based on the fifth of the Japanese elements namely "Kyu" (Void) but it is renamed as "Kyomu" in the anime. Void magic, as implied in the series, is an element which does not focus on elemental magic (i.e. Fire, Water, Earth and Air). If they don't operate on the usual condition than Void branch might be the branch the breaks the border between magic and science as most spell deal in universal laws like explosion, haste, world door, mind wipe.
Since it is very rare, there have been only four Void users and familiars after Brimir has passed on. When a Void user or his/her familiar dies the power of the Void moves on to another host.
These users and familiars are:
- Louise Francoise de La Blanc de Valliere, also known as Louise the Zero, a Noble and second-in-line for Tristain's throne (Henrietta's proclaimed sister); Her familiar and most loyal protector (not to mention her most important person) is Saito de Chevalier Hiraga, the Gandálfr, or the Left Hand of God.
- King Joseph de Gallia, the current king of Gallia (before being dethroned in Volume15); His familiar is Sheffield, the Mjöðvitnir, or the Mind of God.
- The Pope of Romalia, Vittorio; In the light novels, it has been confirmed that Julio Caesar is his familiar, the Vindálfr, or the Right Hand of God. This is now explored in the anime (season 4, episode 1).
- The last Void Mage is confirmed to be Tiffania. Also, she has knowledge of the Void magic, its users and their familiars. She had once accessed Jospeh's music box, which she plays as a song in Princess no Rondo. As she is a half-elf and also Albion royalty (Henrietta's first cousin; Tiffania's father, the Archduke of Albion, is Henrietta's father's younger brother). Her familiar is also Saito, having summoned him as a familiar despite already contracted as one. Her Familiar is the Heart of God (リーヴスラシル, Rīvusurashiru, Lífþrasir).
- Josette, Tabitha's twin sister, became the Void User of Gallia, as the power of the Void went to her after Joseph's death. Her familiar is also Julio Caesar. Her familiar is the Mjöðvitnir, Mind of God.
It is possible for the Void Users to know spells each other already knows, with Joseph at one time casting Explosion to destroy his entire palace with one spell and taking more than 80 mages after him along with the palace and its serving staff. There are differences between spells however, where Louise's Explosion tends to go for power and large-scale, Joseph's Explosion is more accurate but have less power; Louise's Explosion would be to destroy the entire palace with one attack and blow it to dust at her most powerful moment, Joseph blew all the supports and foundations at its weakest points simultaneously to collapse his palace. Joseph's successor, Tabitha's twin sister, Yosette, can also cast Explosion, and according to Vittorio it is even more powerful than Louise's version; so far unconfirmed as she has yet to be seen to cast Explosion.
Void Spells that have been used so far in the novels include:
- Teleport (only able to teleport to as far as she can see; but is capable of being cast rapidly unlike Illusion. The distance depends on how much of the incantation she chants before using it)
- World Door (creates a magical door between one place and another)
- 'Mind Wipe' (two kinds shown so far - ones that can destroy memories of events, and another that can destroy magical compulsion on the mind)
- 'Scrying' (only into Saito's world)
- World's Gate (capable of opening a gate/portal into Saito's world - but takes up a lot of willpower when cast)
- Record (makes the subject relive a memory of the past. Joseph was treated to a memory from the Earth Ruby, where he saw how his brother actually felt when Joseph was appointed to the Gallian throne)
- 'Haste' (speeding up his movements faster than even what Gandálfr Runes can boost Saito's speed)
- Explosion (more accurate than Louise's, but not as powerful)
(The first 2 spells listed here come from Volume 14, and is currently the only spells shown so far by the Founder as of Volume 20)
- Explosion (Brimir is capable of casting explosions the same size as the one Louise used to destroy the Albion invasion fleet repeatedly, and with plenty of willpower to spare after casting)
- Portal (moving groups of people and belongings from one place to another, but cannot cross worlds like World's Gate).
Along with the rings, each Brimiric nation holds a item of the Void, also called 'Founder's Treasure'.
- Tristain possesses the Founder's Prayer Book, that records Void spells, Void magic theory, and Brimir's will to his successors.
- Albion has the Music Box, that plays a song only Void mages can hear if they also have the ring.
- Gallia has the Incense Burner, which its current use is unknown.
- Romalia has the 'Founder's Round Mirror', that allows the user to look into the past and see Brimir's life. This is so they can follow in his footstep and finish what he has started. It was used by Sheffield to take/copy Louise Void power and give it to King Joseph Gaul.
When the four rings and the four treasures are gathered along with four Void mage and four Void familiars, it is said Brimir's Void will 'awaken'.
- Sheffield's magical creatures seem to have a same rune that glows like hers. Her power as the Mind of God allow her to use any magical artifact, and gives her insight into magic theory.
- A Gandálfr has the powers to successfully use any material designed and used for weaponry as well as scientific applications.
- A Vindálfr has the powers to communicate with and command animals.
- The Heart of God ( リーヴスラシル) has the name meaning 'Life' in Ancient Halkeginian language. This familiar is technically a vessel for magical power used by Mjöðvitnir to fill up with magical power while Gandálfr guards the ritual. Then Vindálfr will transport the vessel to where the enemy is and release the spell, resulting in the genocide of a entire race. This was done repeatedly 6,000 years ago when Brimir was forced to do so to prevent the Human race on Halkeginia from being erased. In Volume 7 Chapter 11, and also Volume 19 Chapter 7, Brimir revealed he was so guilt ridden over what he had to do to his 4th familiar he cannot bring himself to even speak this familiar's name.
- It is confirmed in Vol20 Ch6 that the four nations left by Brimir have fixed familiars; Tristain have Gandálfr, Romalia have Vindálfr, Gallia have Mjöðvitnir, and Albion have the 'Heart of God'. For example, a Void User of Romalia cannot give the power of Gandálfr to his/her familiar, only the power of Vindálfr.