High Priest

The High Priest (僧正) is a "bizarre magician", a magic god, who dwells in a territory beyond a certain layer of the world.

The most active magic god that descended the world after Aleister Crowley challenged them, he is the first magic god to negotiate with Touma on the other gods' behalf. After Touma rejects his offer, he becomes the relentless antagonist of the Magic God Invasion Arc, rampaging through Academy City in pursuit of him. Despite all of Touma's efforts, the High Priest proves his power by surviving all of his efforts to defeat him. Only after Kihara Noukan's intervention is he defeated and finally killed.

Etymology
The High Priest's title (僧正, Sōjō) is used to refer to a Buddhist high priest.

Appearance
The High Priest is old and skinny with grey skin covered in wrinkles like the dried branches of an ancient tree, the product of. His eyes have black sclera and green irises. He wears a purple Buddhist priest's robe with a gold over it, the robe giving him a more voluminous outline. He also carries a gold sword which he uses like a walking staff. These accessories are based on those of the Buddhist deity, forced on him by the ones who sabotaged his attempt at reaching Buddhahood.

Personality
According to Nephthys, the High Priest is kind when it comes to judging others, something which comes from him looking down on everyone. He has a tendency to rewrite his definition of what's right based on how he is feeling at the moment and isn't even aware of it, believing that his thoughts are all connected by a continuous thread of logic. He feels joy in tormenting the weak but isn't aware of it on the surface.

Background
In the past, as a follower of the Japanese variety of Buddhism, the High Priest subjected himself to self-mummification, starving himself so his human form would transcend the six paths, becoming a in just one generation, in hopes of saving all people. However a faction opposed to him becoming a Buddha sabotaged his attempt and twisted as a result, he became a Magic God instead.

At some point, he joined the true Gremlin, one of the younger Magic Gods among the group. At another point, he was somehow involved in the death of Aleister Crowley's daughter.

Magic God Othinus Arc
In the Hidden World, just as Othinus was about to break apart before Touma's eyes, it is the High Priest that intervenes in order to save her from her demise. He, Nephthys, and Niang-Niang later discuss the aftermath of Othinus and Touma's journey in Denmark. They discuss their plans in interfering with Touma's development and show concerns about affecting the world of humans due to the sheer effect their mere existence will bring upon it if they did so. Their conversation is interrupted by the arrival of Aleister Crowley into the Hidden World. One of the magicians, referred to as "someone" with a hoarse voice, comments on how if Aleister turned his obsession in destroying magic in the right direction then he too would be part of GREMLIN. Aleister says that he made adjustments to himself that it would not happen, as such he can control something different than them who can only live in a distorted phase. The magician with the hoarse voice asks if science is really wonderful enough for Aleister to indulge himself to that extent. Aleister then comments on how even if took them an eternity, none of them would understand. The magician with the hoarse voice then asks if it has nothing to do with "the single remaining tear stain in his journal".

Aleister is silenced by this, and all remaining expression on his faced vanished as he calls upon his magic name Beast666 and draws out his magic staff. The magician are unperturbed, one of them comments on how is envious of his emotion, though says he should stick around as he says he is about to tie it all together. He tells him that Aiwass, the cornerstone of his plan that he tried so hard to raise is a complete failure and that Aleister will be at his wit's end before long. A moment later, Aleister attacks them.

The battle with the magic gods leaves Aleister's body terribly damaged. However, the attack was all but a ruse to allow Aleister to kill them, switching the spell that Zombie (another magic god) had, which would allow magic gods to go to the world of humans without affecting it by the sheer power of their existences.

St. Germain Arc
With their Hidden World lost, the High Priest, Nephthys, and Niang-Niang descend into the human world after using Zombie's spell, unaware that Aleister has already played his hand. They arrive just in time as St. Germain begins his antics in the Dianoid. Despite really wanting to interfere, especially since Kamijou Touma is in the the Dianoid as well, they are unable to do so as they are still too powerful to do so and would've likely destroyed the world in the process. Much of their actions is just walking around Academy City and observing the events that are unfolding with regards to St. Germain.

After St. Germain's defeat they are ready to interfere with Touma's development. However their plans come to a standstill when Aleister Crowley communicates with them. They once again mock him but they are suddenly skewered by stakes through their chests. Shocked that they could be harmed, Aleister Crowley reveals that he had swapped the spell Zombie used to allow them to be in the world without destroying it with his own, allowing them to be vulnerable to him, and declares that he no longer considers them a threat. At that moment, Kihara Noukan catapults the body of Zombie, crucified on a steel cross and wrapped with barbwire, into their midst.

Magic God Invasion Arc
On December 3rd, the High Priest made contact with Kamijou Touma at A Certain High School, putting a letter in his locker to call him to the roof, which Touma initially mistook to be a love letter from a girl. The High Priest explained what he and the true Gremlin wanted of Touma, and requested that he become their 'scorer'. On being rejected, the High Priest attempted to persuade Touma through destruction. This resulted in a destructive chase through Academy City, with Touma fleeing the High Priest on an acrobike, together with Misaka Mikoto.

Eventually, in School District 23, after trying to destroy the foundations of Academy City, the High Priest was launched into space by a mass driver. Seizing control of the passing Arrowhead Comet, the High Priest attempted to crash it into the city but before he could do so, he was killed by Kihara Noukan, using the Anti-Art Attachment connected to Aleister. Noukan delivered a message from Aleister as he did so, regarding Aleister's daughter whose death the High Priest was involved in, but the High Priest was unable to say 'sorry' before he died.

Abilities
Being a Magic God, the High Priest is powerful enough to risk destroying the world with his mere presence unless precautionary measures are taken. Even when weakened by Aleister's spell, the High Priest is still capable of destroying the world, and invulnerable to most harm.

As a result of his self-mummification, the High Priest has a connection to dirt, formed as what seeped from his corpse as he dried filled the underground space where he sealed himself and starved to death. This connection is linked to the Shinto aspect of dirt being unclean and connected to the underworld being mixed into the Japanese variety of Buddhism that the High Priest followed. The High Priest uses his connection and control over dirt to create giants hands of mud, capable of crushing, uprooting and throwing entire buildings, is able to sense where someone is if they are in contact with the ground, can remove dirt from underground to cause city-wide collapse, and seize control of objects such as the Arrowhead Comet by manipulating the dirt mixed into them.

As one who rose to the level of a Buddha in a single life, he is also capable of manipulating the intersection of the Six Paths. The exact nature and extent of this power isn't fully known. From Nephthys's warning and the High Priest's earlier explanation of the Six Paths, the concept that all souls (human, animal, deva etc) are repeatedly reborn after death until they reach enlightenment and might live their next lives in the six realms as other type of beings, Touma speculated that the High Priest might be able to change the value and rank of souls, or change precedence in a manner similar to Terra of the Left's Execution of Light, but he wasn't able to grasp its true nature.

Equipment
The High Priest carries a golden sword, based on that of Acala, forced on him by his saboteurs. He doesn't use it as a weapon, instead using it as a walking staff.

Character Art Design
According to Haimura, the first thing the High Priest made him think of was Saint Hakushin from, which Version 1 essentially was. After being told he could make him flashier and to remove the headdress as bald characters were so rare, he made Version 2, whose motif Haimura says goes without saying.

Quotes

 * (To Aleister in the Hidden World) “It’s a complete failure, young one. You’re going to be at your wits’ end before long.” (ありゃあ完全な失敗作じゃよ、若造. じきにお主も頭を抱える事になるじゃろうがな.)
 * (laughing) "Uho hoi☆" (うほほーい☆)

Trivia

 * The High Priest is described as having a dried-up voice.