An Unrestricted Spell Insignia (自在式 Jizaishiki) is a crest or pattern which either:
- shows the configuration and flow of Power of Existence of an Unrestricted Spell,
- appears when an Unrestricted Spell is activated, or
- amplifies or supports the effect of an Unrestricted Spell.
Background[]
Unrestricted Spell Insignias usually radiate the color of the user's Power of Existence.
Unrestricted Spells themselves don't have a set form or shape, and can be activated even without preparing an Insignia beforehand by intuitively using one's own powers, so the majority of Crimson Denizens and Flame Haze choose to prioritize using their own powers. However, by using Insignias, the effect of Unrestricted Spells can be increased (as Dantalion says, a "booster"), or supported. Also, in the case of the effect of Anti-Seal, it is possible that once the Insignia is activated, it can generalize the Spell so that any number of people can use the Spell to the same effect.
Insignias by themselves have no effect. By going through the process of loading Power of Existence into them or by activating them while preserving them, Insignias' effects can be activated. Different Insignias have varying degrees of difficulty in their activation, and the more complicated the Insignia is, the harder it is to activate it.
An Insignia, unlike a pure Unrestricted Spell, can be studied by the likes of Unrestricted Spell Masters, be it their shape or pattern or some other aspect. Even if someone can't activate it, Insignias themselves can be carved or engraved into things, and can even be studied by humans, or with the use of humans in experiments like the ones conducted by Dantalion. Inserting Insignias into things is possible without being a Master, as demonstrated by Sabrac inserting the Psalm of the Grand Order into the Reiji Maigo.
Appearance[]
Apart from looking like magic circles, the appearance of Insignias differs greatly between the light novels (and manga and game) and the anime series.
In the light novels, Insignias are configured by parts resembling mechanical components like gears, inside of which is a string of characters which most humans can't decipher, and even if the effect of its activation is the same, the Insignia's density changes based on the practitioner's amount of power.
In the anime, they looked more like stereotypical magic circles, with the string of characters resembling rounded handwriting. There is also no change in the Insignia due to the practitioner's power.
