Satan Soul (サタンソウル Satan Sōru) is a Satan Soul Spell.
Satan Soul is a powerful spell that allows the user to take over the appearance, abilities and powers of a demonic being. When the user activated it for the first time after two years of abstinence, the user released a large Magical blast which destroyed the surrounding area. Satan Soul is initiated by seemingly covering the user’s body in flat, square-shaped scales-like parts, which subsequently disappear, revealing their new appearance.
Whilst using Satan Soul, the user's eyes become darker and their eyelashes grow larger, with a dark, thin marking in a light zigzag-style crossing their right eye vertically; similar markings are present above their right breast and on both of their bare thighs. Their hair becomes wilder, jutting upwards and getting curlier, with the front ponytail growing longer, and their ears enlarging, extending backwards, and gaining pointed edges, bearing resemblance to those of the fictional elfs. The user also gains sharp canine teeth, and their lips become covered in dark lipstick. Their forearms and hands receive noticeable changes, becoming covered in scales and each sprouting a fin-like protrusion on its outer side. The user also grows a large, stocky tail seemingly made of metal plates or scales, getting smaller and smaller near its end.
The user's clothing also changes, with any attire the user might be wearing being replaced by a dark, skimpy one-piece suit, which reveals their arms and legs and is open on the front and the back, exposing most of their belly and wide cleavage. Such clothing has golden-colored edges taking on spiky shapes, and their similarly spiky collar is tied around the neck by a cravat tie. Their shoulders are tied in thin belts protruding from their one-piece suit, and their feet are covered by matching, high-heeled thigh-high boots, which are decorated by lighter motifs on their upper parts, taking on the shapes of jagged blades pointing downwards on the front of their legs, and on the lower parts, in correspondence to their ankles and feet. The user also dons a pair of gauntlets covering the back parts of their transformed arms.
Darkness Magic (闇の魔法 Yami no Mahō): While in this form, the user is able to use Darkness Magic. The user was also shown to be able to use this magic to enhance their physical combat capabilities, create powerful blasts, explosions, shields and even shape it into claw like tendrils capable of chasing after opponents.
- Darkness Stream: The user extends their hand towards the opponent and summons forth their Magic Seal underneath their opponent, where a multitude of large tendrils composed of dark energy is formed, which surround and envelope the opponent. It was used against Freed, who evaded it, thus leaving its full effects unknown.
- Soul Extinctor: The user initiates this attack by gathering energy from the surrounding area between their hands, which subsequently takes the form of a large, black globe. The globe then fires a large black-purple beam that generates a devastating explosion. This spell was strong enough to defeat Freed, who no longer had his Dark Écriture: Darkness and Dark Écriture: Wings spells active after its blast. There is also a variety to it, in which the sphere, seemingly created faster, is focused around the user's hands and forearms and shot in a less powerful, yet still destructive blast.
- Evil Explosion (エビル エクスプロージョン Ebiru Ekusupurōjon): The user holds their hands together and a dark colored sphere gathers on their palm. When fired, it is fired from the user's hand. The receding explosion is devastating. This spell was powerful enough to almost completely destroy Azuma's Tree Shield. However, he himself received little to no damage.
- Demon Blast: A large ball of dark energy is charged between the user's hands, from which a dark purple beam is fired towards the target.(Unnamed)
- Satanic Blast: The user raises their hand above their head and starts charging Darkness Magic in the form of a sphere that grows larger as it charges. The user then aims their hand at the target, sending a large blast at the target that then becomes a huge pillar of Darkness Magic covering the entire area. (Unnamed)
- Dark Deflect: Focusing the incoming attack on their eye, the user redirects the incoming spell, missing the intended target. (Unnamed)
- Evil Explosion (エビル エクスプロージョン Ebiru Ekusupurōjon): Using their Magic Power as a medium, the user lifts a body of water, even one as big as a river, with their arms, and then starts rotating, sending the water flying towards their foe in a powerful whirlpool.
- Evil Spark: A melee spell in which the user extends both of their hands to touch the opponent, subsequently channeling electricity through them.
Flight: In this form, the user is capable of sprouting a pair of wings from their back at whim, which allow them to fly. Such wings are reminiscent of a bat’s, and come with small spike-like protrusions on their upper edges.
Enhanced Durability: This form increases the user's natural durability, allowing the user to take multiple powerful explosions from Azuma in consecutive reprises, emerging almost unscathed and remaining active to continue the battle.
Enhanced Speed: While in this form, the user's speed increases to the point where, after sprouting their wings, the user could easily deliver a powerful punch to Freed, even with the help of his own wings and a large distance between them, before he could react. During the user's fight with Azuma, the user could similarly deliver a powerful kick into his stomach before he had the chance to react.
Immense Strength: When employing their demonic powers, the user's strength is increased to the point where they can easily break through solid rock with their punches. When their fist clashed with Freed’s while the latter was in his own demonic form, a powerful shockwave was generated, which destroyed the ground below them. The user was also able to block a punch from Elfman while he was in Full-Body Take Over with one hand.
Poison Resistance: This form allows the user to have a high resistance against poison, going as far as inhaling the poison gas and calling it a treat.