This idea is inspired by the spirits from the Tales of series
Ive got the prologe but thats all ive got its up to you to make the story be warned its really long
Before the time of the gods since beginning of all their were the spirits. The first of the spirits were the Great Spirit of All Things or the Great Spirit of the Void (which grants him dominion over that which came before existence) Origin is both but through time his title over the void was forgotten (also known as King of the Spirits), Chronos Great Spirit of Time. Then came the ancient ruler of the elements Maxwell the Lord of Spirits (bar Origin and Chronos) who watches over the spirits. Next was the Great Spirits of the Elements: the ruler of hellfire Efreet Great Spirit of Fire, the maiden of the mist Undine Great Spirit of Water, the servent of mother earth Gnome Great Spirit of Earth, the heavenly messager Sylph Great Spirit of Winds, the light of the heavens Luna Great Spirit of Light (Luna is also the Great Spirit of the Moon and she sheares the title of Great Spirit of Light with Aska but it has been forgotten that Luna is also the Great Spirit of the Moon and only know her as Great Spirit of Light and she does nothing to remind the people of her dominion over the moon), the hammer of godly thunder Volt Great Spirit of Lightning, the desiple of everlasting ice Celsius Great Spirit of Ice, the envoy of the dark abyss Shadow Great Spirit of Darkness. Then came lesser spirits which are abundent some serve the Great Spirits, but many are loose free in the world they help people cast what is know as Spirit Artes.
Spirit Artes can be categorized as martial or magic artes they can be done by channeling mana to the spirits. Both martial and magic artes may incorporate one or two elements or none at all. Mana is a substance ir energy that gives life to all and can be channeled differently some channel it mentally to cast spells others channel it through their weapons few choose to do both but it is impossible to do both at the same time hence the two types of artes. Some of the more experienced or trained users can channel the mana in the air around them with their own only spirits can solely channel mana in the air without using their own as they are entities made entirely of mana, channeling mana from the air is a slower process then channeling mana from ones self but is requires for the more powerful magic artes. Their are different ranks of artes martial artes are ranked as either basic or arcane arte while magic artes are ranked as novice, intermediate, and advance spells. Though two arte users who are in-sync maybe able to perform a linked arte as it stats it is when they combine their artes for a more powerful version of it it may be different then what one would expect as a linked spell arte may make an entirely diffrent spell. As arte users battle their battle spirit grows and when their battle spirit reaches it peak they get a sudden burst of energy this is known as an Over Limit this burst is temporary. In Over Limit they can attack and cast faster stronger fighter may even beable to shrug off hit (this does not mean they are immune to damage as the wounds will effect after the Over Limit passes) only very experienced fighters are able to store their Over Limit for later use and can activate it at will. During an Over Limit users can use artes of two different rank these are Burst Artes and Mystic Artes most only have one type of burst arte do to fighting style preference be it magic or martial but it can be changed if given an element these are Altered Burst Arte. Mystic Artes are artes created personally by the user as no two users have the same Mystic Arte that maybe named the same but how its done or what it does will be different some have been able to obtain more then one Mystic Arte and very few can do a Linked Mystic Arte this can only be done by the closest of partners with absolute trust in each other Mystic Artes. Both Burst and Mystic artes can be initiated by performing an Arcane, Intermediate, and Advanced Arte also Mystic Artes can be initiated after a Burst Arte but all Mystic Artes end the Over Limit after it is performed. If two people are in Over Limit at once they can link up for the duration of the Over Limit. When one is linked they can perform Linked Artes one after another, but lose the ablitity to perform Burst Artes however Linked Artes can initiate one of the linked pairs Mystic Arte. Over Limit is the only time when users of martial artes can channel the mana in the air to perform artes.
Many of the Great Spirit allow one to make a summoning pact with them based on a vow they are know as Pact Makers by the Great Spirits, but are known as a Summoner to everyone else and the Great Spirits that do this are also know as Summon Spirits. Should the vow be broken by the previous Pact Maker the Great Spirit may annul their pact and esablish a new pact with a new Pact Maker. This can also be done if the previous Pact Maker has passed but the spirit can not say if that is the case or not. To make pact with a Summon Spirit they are put to a test of mind and body to see if they are worthy. The first test the Summon Spirits have for the Pact Maker is a test of the body which is combat with the spirit this maybe done alone or as a group till the Spirit deems (when making a pact with the Great Spirits of Light they must fight both Luna and Aska but only Luna makes the pact) the Pact Maker or their group worthy their have been cases where life is lost. The test of the mind is the vow the Pact Maker makes to the Summon Spirit this is where the they are judged by heart and mind, but if deemed unworthy they can refuse the pact. If has been know that the test of the body can be done multiple times should the Pact Maker fail, but it is not known if the test of the mind can be redone as the test of the body is always first. It takes alot of mana to summon a Great Spirit for combat and is usually left as last resort or as a trump card, but if in Over Limit they can be summoned with much ease otherwise the Pact Maker will be drained and tired. Pact Makers can mentally communicate with their pacted spirit and with the pact with Undine and Sylph the Pact Maked can fly in the wind and BE JESUS (water walking) but only after a pact with Maxwell is established.
Their was once a Pact Maker on a journey who had befriended an artificial summon spirit, named Corrine, (way to make artifical spirits have been erased after he was made and it had become forbidden to attempt again) but during the journey it sacrificed itself to save the Pact Maker leaving behind a momento, but near the end of the journey they had felt something calling for them so they followed it and it had led to a place where a naturally high concentration of mana resides there the momento began to glow and transformed into Verius the Great Spirit of Heart he who watches over life unlike most of Great Spirits he chooses to not make a summon pact as he chooses to watches over life. Though should the Pact Maker finds themselves or those close to them in mental turmoil on what to do or have trouble within their mind and souls (like split personalities) they may visit Verius for advice or help, but if they wish for Verius to help it must be done with all their heart. As with Verius their are a few Great Spirits that aren't Summon Spirits those are Martel the Great Tree Spirit the gaurdian of the world tree Yggdrasil (Norse tree will be named after this and are not the same thing) which fills the world with mana and helps keeps it alive (mana and nature energy are different) only the Great Spirits know where it resides, Pluto the Great Spirit of Eternity and True Ruler of the Underworld (unknown to devils and added true cause Great Red is True Red Dragon Emperor so to keep Satan as Ruler of the Underworld) he was sealed by Maxwell long ago but he could break free at anytime he is laid back for a Great Spirit and enjoys roaming the world in his incarnations (incarnation isnt gender locked but Pluto himself js locked as male) (you could have him befriend and/or chill with Azazel whether you have Azazel learn of the spirits through this is up to you but if not he cant know till the Pact Maker goes public in the moonlit world) though should the world become endangered he will test the worth of the one(s) who can save it and if things go south as a last resort he will break the seals and do it himself (he can freely travel to and from the underworld completely undetected), and finally Muzét Great Spirit with dominion over dimentions Muzét is a relatively new Great Spirit at the age of 20 over the others with centuries of age as such she is very curious about many things mainly food shiny things and human emotion and interactions she used to reside in the dimention gap but unlike Orphis who was kicked out she got bored and follow Orphis to the DxD dimention (yes im calling it that deal with it) being young she depends on orhers for guidance (she had ask Great Red what she should do and he said to follow Orphis and find something that interests her) she roams the Earth watching people and occasionally stealing food from festivals and events (as for why Orphis hasn't recruited her for the Khaos Brigade for her power she annoys her and her threats do nothing to Muzét) she may see the Pact Maker as a younger brother/sister (you can choose which) should she cross paths with the Pact Maker when they are in trouble she will help but then afterwards she will continue to roams the world or not up to you but with control over dimentions she is OP for the world (underworld included). (These three Great Spirits dont need to be in the fic just thought i should mention just incase)
Alas over time like may things people started to forget the spirits cause of the course of technology and the Rise of the Gods. People has slowly lost the ability to see the lesser spirits to the point where basically no one can see them even the gods have forgoten of the spirits in their arrogance (bar Orphis as she resides in the gap and can see through dimentions and Great Red cause he has powers over dream) (the Great Spirits physical form is made from the concentration of a large amount of high quality mana that all can see but thay choose to remain hidden unless it becomes time where they are needed or are called upon by Pact Makers and if they freely form it would be with in their domain). The pantheons that rely on, incorporate, or are based on the concept of spirits only refer to spirits of the dead and/or of nature though rarely few lesser spirits of old have been seen or interacted with are mistaken for those of the dead or of nature. Though there lies a village in Japan where the residents that live there remember the spirits of old that have lived since before the Rise of the Gods and retained the ability to freely see the lesser spirits. In this village they choose one to be trained to become a Pact Maker incase their comes a time where they are needed to keep peace and balance to the world. When ever the village is attacked by one from the Moonlit World (supernatural world) the spirits are mistaken as Summon type Sacred Gear but they dont ever live to tell of their "discovery". The village have kept the exsists of the spirits secret since the time people compleatly lost the ability to see the lesser spirits and hence trained in the ways of the shinobi and for the Pact Maker the arte of sealing as well. Both with the implication of Spirit Artes as well. There can only be one pact maker at a time.
The Great Spirits seek peace of the world but can not do much as they have been forgoten and can not upset the balance of the world themselves so they rely on pact makers but it is rare that one is worthy of the pact. But now the spirits feel that their is a force that threatens to upset balance of the world and may very well lead to the end of all the new Pact Maker now has to venture out to find and stop it from happening (refering to 666 cause thats a thing and Cao Cao's plan to eradicate the supernatural or something like that) now it is the time for all to remeber those that have always been to remeber the exsistance of the spirits. Who will join the Pact Maker on this quest. (Side note if made devil Luna protects him from light poison still burns but wont kill them unless it his vial areas think of it like how holy water just irritates Rin in Blue Exorcist)
Origin Maxwell and Chronos can only be summoned for a breif amount of time as they are too powerful to stay summoned
Summon Spirit Chants
I Call Upon The Maiden Of The Mist I Summon Thy Undine
I Call Upon The Heavenly Messengers I Summon Thy Sylph
I Call Upon The Red Giant The Ruler Of Hellfire I Summon Thy Efreet
I Call Upon The Light Of The Heavens I Summon Thy Luna
I Call Upon The Hammer Of Godly Thunder I Summon Thy Volt
I Call Upon The Servant Of Mother Earth I Summon Thy Gnome
I Call Upon The Disciple Of Everlasting Ice I Summon Thy Celsius
I Call Upon The Envoy From The Dark Abyss I Summon Thy Shadow
The Source Of Heaven, Earth, And Everything In Between The Ruler Of All I Summon Thy Origin
Ancient Ruler Of The Elements I Summon Thy Maxwell
He Who Watches The Of The Flow Of Time I Summon Thy Chronos (Chronos chant is made up)
Doesnt need to be their symphonia models (bar Origin and Maxwell)
Feel free to add other elements from other places but the spirits and artes must be the main focus for the main OC