Kyo Ethnina/Powers and Abilities

Abilities
He was a genius, able to study, control, and go around many phenomena, including the summoning of an artificial Wave of Catastrophe, controlling Spirit Tortoise's power, etc.

He held the Vassal Book against its will and was well versed in its power. However, since his vassal weapon opposes him, he wasn't able to use all of his powers, and even after implementing many more power up methods than the other heroes, the true chosen heroes were still able to fight against him.

Most dangerous among his abilities though is his status as a Reincarnated individual. Whenever he dies his soul is able to wander free of his body to take on a new one, oftentimes the homegrown humonculi that he has made and modified specifically for the purpose of housing his soul and improving on his original.

Spirit Tortoise
A spell which summons a mandala pattern in the surrounding area, in said area Kyo can control gravity itself and immobilize enemies along with their projectiles. However, if the mandala pattern on the ground is disturbed, the effect weakens. This spell is powered by the Spirit Tortoise. Creates the same cross-dimensional rifts that manifest during the waves. This allows Kyo to transport between Raphtalia's World and Glass' World as he pleases. He can also use it to force others to teleport or can lay traps in the spell like the one that sent Naofumi and Rishia to the Infinite Labyrinth. It seems like this skill is powered by the Spirit Tortoise energy.
 * Unnamed Gravity Field Ability
 * Waves of Destruction: Dimension Wave「災厄の波・ディメンションウェーブ Saiyaku no Nami Dimenshon Ueebu (lit. Waves of Calamity - Dimension Wave)」

Vassal Book
Kyo was initially thought to be the rightful user and owner of the Vassal Book, however, it became known that he wasn’t and the Vassal Book itself resisted him whenever he used it. This resulted in him not being able to access all of the books abilities.

Offensive Skills

 * Composition Form One: Bird of Flame「文式一章・火の鳥 Bunshiki Isshou Hi no Tori (lit. Composition Form Chapter One - Phoenix)」

The Pages of the Vassal Book gather into one place, transforms into a flaming bird before shooting towards the target. Kyo throws a glass bottle which shatters and release a puff of green smoke. The spell's targets are strengthened as the air fills with the sound of buzzing insects.
 * Expanding Composition Form Six: Invigorate「拡張文式六章・活性 Bunshiki Rokushou Kassei (lit. Expanded Composition Form Chapter Six - Invigorate)」


 * Redacted Skill「文式五章・列破 Bunshiki Goshou Reppa (lit. Composition Form Chapter Five - Blast Line)」

A flutter of pages creating strong shockwave that expands from Kyo. This skill is for some reason not written in OPB's translation of Volume 7. A possible name for this skill considering how vassal book skills are usually translated would be. Composition Form Five: Blast line. The Vassal Book launches a stream of pages to cut into the target. Kyo considers this the most basic composition of the Vassal Book. This skill apparently did have a name in the Japanese version of the novel, and a possible name for the skill considering how Vassal Book skills are usually translated would be. Formation One Form One. This skill summons a roaring flame in the shape of a demon. This construct of flames then charges toward the target.
 * Unnamed Flying Page Attack「一式一章 Isshiki Isshou (lit. Form One Chapter One)」
 * Composition of Flame「業炎の章 Gou En no Sho (lit. Chapter of Karmic Fire)」
 * Unnamed Yuki-onna formed Ice Skill

Following that comes another skill that summons freezing ice in the shape of a Yuki-onna which charges towards the target. This skill is supposed to come after the skill Composition of Flame where it charges towards Rishia from behind Rishia (to which she destroys with the hilt of her sword) but it was mistranslated as swords of ice that flew from the back of the room.. The anime has it depicted to be part of the skill Composition of Flame. A skill that turns an opponent's magic power into flames that fall from their body, their SP bleeding out with it. A skill that turns an opponent's magic power into murky winds that form with their body as the epicenter. An ability that uses the enemy's attack power and creates blades of light that damage them. Turns the surroundings into a white room, and Kyo can bombard an opponent with many kinds of magical attacks from every angle. Summoning birds made of lighting and fire, energy beams, and boulders all at once. A cage emerges from the pages of the Vassal Book which can ensnare its targets A continuation of Composition Four: Constriction grow on the ceiling of the cage which then rains down on the captured targets. A skill which fires lighting from Kyo's pages which homes in on targets.
 * Flame Formation: Magic Explosion「炎式・魔力爆裂 En Shiki Maryoku Bakuretsu (lit. Flame Form - Magic Power Explosion)」
 * Rot Formation: Magic Explosion「腐式・魔力爆裂 Fu Shiki Maryoku Bakuretsu (lit. Decay Form - Magic Power Explosion)」
 * Light Formation: Force Explosion「力式爆裂 Riki Shiki Bakuretsu (lit. Force Form Explosion)」
 * Libraria「ライブラリア Raiburaria」
 * Composition Four: Constriction「縛式・四章 Baku Shiki Yon Shou (lit. Constriction Form - Chapter Four)」
 * Composition Four: Constriction → Continuation: False Ceiling「連式・吊り天井 Ren Shiki Tsuri Tenjou (lit. Linking Form - Crushing Ceiling)」
 * Composition Eight: Divine Punishment「第八章・天罰 Dai Hasshou Tenbatsu (lit. Eighth Chapter - Divine Punishment)」

Curse Series
An ability from the Vassal Book curse series. Kyo fires feathers from his book, which then all release small energy beams that come together and form one big black energy beam to fire at an opponent. Some feathers can also be used to heal Kyo's wounds.
 * Forbidden Composition: Revelation「禁断の書・黙示録 Kindan no Sho Mokushiroku (lit. Book of Taboos - Revelation)」

Anime Exclusive Skills

 * Nameless Sword

The user grabs a page from the book and it then transforms into an energy sword that can be used for close combat.