Summon Elemental

is a magical power possessed by Chion and Ironside.

Description
This power is a form of, a user of which is called. Its use allows Chion and Ironside to conjure forth elemental "Spirits" to aid them in battle, which control and naturally dwell within the four elements: wind, earth, fire, and water. According to Ironside, one can distinguish between "low-ranking Spirits" and "high-ranking Spirits" (e.g., "Sylphs" being low-ranking Wind Spirits that are governed by the high-ranking King of Wind, called "Djinn").

Chion has noted that Spirit Arts, in terms of incantations, require the most precise pronunciation within the entire magic system. At least in Chion's case, his four Spirits are kept contained within gemstones of varying shape, and he can summon them from within (or force them back into) the stones at will. Lower-level spirits like Chion's can be scared into retreating back into their vessels (or instead, into hopping out of them) if they sense the presence of Spirits of higher rank, such as Life Spirits.

Life Spirits, the highest-ranking of all Spirits, can also be summoned by a user of this power, though at greater cost. Ironside used Spirit Arts to transfer a powerful Life Spirit into Percival's deceased body by sacrificing a large chunk of his own lifespan. Ironside's goal was to use Percival's resurrected body to become the "receptacle" for the soul of his son, Diodra, who was already suffering from fragile health due to the negative miasma released by the Demon King during the New Holy War, which had already killed Diodra's mother.

Chion

 * A low-ranking Wind Spirit whose small body is composed of one rapidly swirling twister of wind; it has two arms, a tail, and two glowing eyes hiding underneath its windy exterior. Chion keeps this Spirit contained within a polygonally cut gemstone.
 * This command makes Sylph trap the air around the target's head, blocking their voice and/or hindering their ability to breathe.
 * This command is used to make Sylph relay sounds to the user from a distance.
 * A low-ranking Earth Spirit of small size and humanoid shape, made of earth and bearing a face like a bearded old man's. At the user's command, the Gnome can grab hold a target with large arms formed from the ground, in order to restrain and, if Chion wishes, crush and entomb them. The stone containing Gnome is a small cluster of pointy crystals.
 * Gnome hides underground so that it can grab an opponent from below, forcing them to bow down and leaving them open for subsequent assault.
 * A low-ranking Fire Spirit resembling a flame-bodied lizard or diminutive dragon, complete with small wings. The Salamander can breathe fire, and Chion keeps it within a dark, spherical gemstone.
 * This command is used to make his Salamander chase down a designated target by following their blood's scent.
 * Chion has his own Salamander call upon all of its kin that dwell in nearby fire sources (like torches), making them rise up into the sky and fuse into one giant firebird that rushes past and incinerates a target, the resulting explosion resembling a firework.
 * Unnamed Spirit of Water: This low-ranking Water Spirit takes the form of a small girl with a body made of water. It is contained within a small, elongated crystal with sharp points, akin to an icicle.

Combined Techniques

 * Chion immobilizes the opponent with Gnome to allow Isolde to place Time Bombs on the target.

Ironside

 * A high-ranking Wind Spirit under Ironside's control, described as the . It takes the form of a giant humanoid which, like lesser Sylphs, is made entirely of swirling winds, which completely make up its bulky body, arms, and queue-like braid; its head is seemingly made of more stagnant air, revealing the entity's clear features. If Ironside keeps the Djinn stored within a stone like Chion is currently unknown.
 * Star-Shaped Slashes: Using what he dubs, Ironside can project invisible slashes (originating from glowing stars of light in the air) with simple hand gestures, usually swiping his outstretched index and middle finger. These slashes (likely made of air) are very potent, able to tear through human flesh and carve up bedrock easily. They are mainly used offensively and can also serve to counter enemy attacks, dispersing them. Thanks to his well-honed technique, Ironside can direct the path of his slashes with precision, able to pursue a rapidly flying target with them. Yet, despite their apparent power, the "Djinn's Blades" were unable to scratch Ban due to his vastly superhuman resilience. In the anime, the star shapes have a red-glowing color scheme.
 * Raising his hands to bring forth the "Djinn's Blades", Ironside spawns a myriad of small, twinkling orbs in the air around his opponents, which then expand into larger star shapes to cut his opponents to ribbons.
 * By whirling his hands around, Ironside channels his power to create an invisible downforce, strong enough to open a massive hole in the ground.
 * Allows Ironside to float in midair, seemingly creating a cushion of wind that he can also use to break a fall.
 * This command materializes the Djinn around Ironside, the Spirit granting its summoner elemental "protection" by cloaking him in wind.
 * This command makes the Djinn expand its own body to engulf the immediate battlefield within a spherical wind barrier. This traps a given enemy while serving as a medium for Ironside to unleash subsequent wind attacks inside, like Belfest Margot.

Trivia

 * "" are mythical creatures aligned with the elements of nature. Occult and alchemy texts from around the time of the European Renaissance talk of invisible, partly physical "spirits" that correspond to the : air, earth, fire, and water. The 16th-century Swiss alchemist  four classes of spirits accordingly:  (earth spirits),  (water spirits),  (air spirits), and  (fire spirits).
 *  (Arabic: جِنّ‎, jinn), also romanized as djinn or anglicized as genies, are intelligent spirits in Arabian and Islamic mythology, sometimes associated with the wind.
 * It is possible that Ironside's flying row boat is kept afloat through his Wind Spirit's power; the boat's underside is marked by a starlike pattern resembling the Knight's star-shaped slashes.