Seraphiel

 (Hebrew, שׂרפיאל; 終焉明星, Shuuen Myoujou, Morning Star Demise), oftentimes referred to as Myōjō Shūen, was a famous (or infamous) Seraph-ranked Youshun Tenshi who rose to prominence in the Great Tougenkyou War as a staunch supporter of his liege lord, Tenshi God-King Michael, evidently serving as the High Commander of Michael's Honour Guard. With Lucifer's death and Michael's self-imposed exile to parts unknown after the conclusion of the Great Tougenkyou War, the leaderless Tenshi elected to serve as the first Overking.

Seraphiel peacefully ruled the Tenshi with the aide of his closest confidant, Yahoel. In addition, Seraphiel served the Queen Regnant of Tougenkyou, Yuu Hoshiko, alongside Kiyoko Takara as part of the Inner Council, assuming an advisory role to Yuu. However, the time of peace came to an end when Grandmaster Inbouka Magatta suddenly murdered the vast majority of the Tougenkyou Guardians in an effort to attain enough power to break through the Last Door containing the Well of Awakenings. It was during this time that Seraphiel underwent a mysterious personality change and initiated a campaign to conquer all of Tougenkyou for the Tenshi Dominion. Those who resisted or attempted to flee were mercilessly killed, with Seraphiel personally executing the so-called rebels himself. In his insanity, Seraphiel unknowingly became a Datenshi and declared all the Tenshi as enemies, proceeding to massacre entire populations, with the Ryuu Tenshi being hit the hardest. Before the Tenshi were rendered extinct to the Fallen King's actions, the half-Tenshi Misaka Tennyo interfered and fatally struck down Seraphiel.

Much to the dismay of Misaka Tennyo and Yahoel, Seraphiel was revealed to be a mind-controlled pawn of Inbouka Magatta since the onset of the Great Guardian Purge, having been put under a spell by a Lucifer-influenced Inbouka. As a result, Seraphiel was unable to resist Inbouka's commands and was painfully aware of all his actions, including the massacres of his beloved people. In his final moments as King of the Tenshi and as a form of repentance for his folly, Seraphiel commanded Misaka to focus the hatred of all the Tenshi onto him, which forever marred his reputation into infamy and marked him as a Destroyer instead of a Savior.

Personality
Seraphiel possessed a deeply ingrained hatred for the Ryuu Tenshi. Inbouka Magatta manipulated Seraphiel's hatred

Powers and Abilities
Immense Wisdom Energy:

Kenmei Kosaku Mastery:

Expert Bōjutsu User: Known as Staff Technique (棒術)

Ultima Aditum
Mamesenshi (忠実戦士, Devoted Soldier) was the name of 's Ultima Aditum and was said to represent Myojo's Loyalty to his liege lord, Tenshi God-King Michael and to the Tenshi. When fell and became a Datenshi, Mamesenshi became grotesque and distorted in order to mirror the changes. Unlike the Tenshi who preferred to keep their Fuainaru Apurōchi internalized, Myojo chose to seal it in the form of a highly stylized staff.i

Mamesenshi later came to be known as Fushinsenshi (不臣戦士, Disloyal Solider).

Fuainaru Apurōchi Special Ability:
 * Tsukinami (月波, Moon Wave):
 * Getsuei Kakou (月影下降, Moonlight Descent):
 * Unyu (運輸, Transportation):
 * Kansei (管制, Control):

Trivia

 * Like with Inbouka Magatta, it was widely believed that Lucifer had seduced with promises of power, and thus influenced his downfall. However, this was later proved to be untrue when it was revealed that Seraphiel was under the control of Inbouke Magatta during the entire duration of the Great Guardian Purge.
 * Due to his innocence being revealed at the end of the Great Guardian Purge, Seraphiel was unlikely consumed by The Reaper, the God of Judgement. Kiyoko Takara believed that Seraphiel was reabsorbed into the Well of Awakenings, the resting place of all good Tenshi and Kenmeiotome.

Behind the Scenes

 * Seraphiel's namesake was based on Seraphiel, an angel found in the apocryphal Book of Enoch, where he held the highest rank amongst the Seraphim and is known as the protector of Metatron, an Archangel in Judaism. In some religious texts, Seraphiel was followed by an angel named Jehoel.
 * Seraphiel is a male Hebrew name meaning Prince of the High Angelic Order.