Among Magius Users, there are several known but uncastable spells known as Forbidden Spells (Although they go by different names depending on element). An average mortal's body can not channel enough magius to perform these abilities, but some are not beyond an extremely trained professional User.
Unleashed Fury I: MagmaEdit
Controls magma as smoothly as a water user can control water. The magma can explode from the ground, be thrown in a tidal wave, and rain from the sky
Unleashed Fury II: OverheatEdit
Burn up the oxygen in the air to create searing temperatures in a wide radius, incinerating anything caught within
Unleashed Fury III: SupernovaEdit
Channel so much fire magius into one space that nothing can contain it, releasing a gigantic explosion of fire, capable of destroying anything, melting tempered steel in a fraction of a second, reducing all to ashes
Forbidden Art I: RegenerationEdit
Causes a living body to regenerate freshly missing limbs, organs, etc, restoring it to a perfectly healthy state
Forbidden Art II: ???Edit
Final Forbidden Art: Soul ControlEdit
Causes the soul of the caster's target to come under their control. They may be stripped from their mortal body, or if already dead, channeled into a living body.
Sealed Rite I: MetamorphosisEdit
Reconfigure anything to look like anything else, and contain any matter the caster chooses.
Sealed Rite II: Miasmatic HellEdit
Trap a large radius of victims' minds in a state of torture, causing them to believe they are dying over and over again in the worst ways imaginable, killing the victims from shock
Sealed Rite III: AnnihilationEdit
Unleash Shadoc upon the mortal realm (The physical form, not through a host) to rain his destruction upon all life