The back ground created by GOD was simple in AD 1000 Shortly after the first Christian Millennium, the demons began their large-scale invasion, termed the Incursion, of the world around this time.At that time Angel Raziel appeared to Alexander Raziel making him a Nephilim with his blood,thus making him the first Shadow Hunter.Angel Raziel to help Alexander through his quest gave him the Mortal Instruments to begin the race of Nephilim.These Nephilim's created through the Mortal cup will not be as strong as him,but will have enough strength to defeat the supernatural beings in the world.
Before recruiting Alexander started learning all form of martial arts and sword fights.After becoming a master at it did he move on to studying "The Book of the Covenant" which is a tome given to Alexander by the Angel Raziel containing all the runes they could use in their life and war against demons.The books interestingly updates itself as new runes are found out.
Runes are symbols that grant beings various supernatural abilities. For Shadowhunters, runes are a complex runic language given to them by the Angel Raziel, which grants them powers beyond those of mundanes or normal humans. Runes are burned into Shadowhunters' skin using steles, and are their most common tool in their fight against demons and other supernatural.
There are thousands of runes and Alex because of his potent angel blood is able to create new runes. Alex using the stele burned runes into his skin like Fortis,Heightened speed,Foresight,Recall.....etc
Alexander created a separate book from "The Book of the Covenant",which was known as the "The Gray Book", formally The Book of Gramarye.So that runes or Marks, the Nephilim's are permitted to use have certain restrictions. Alexander even created runes called Congtract runes meants to hold contracts between certain groups or individuals those that break the contract have to suffer said consequences.
After that Alexander went on to recruit 50 members,with slight help from Raziel they were persuaded. The training took 20 years, after the hunt for demons began it was successful, that they started making a name for themselves and churches started to assist in their own way by becoming safe houses meant to lodge and assist Nephilim from around the world in their quest to kill demons.
Demons are malevolent, inter-dimensional beings that travel between worlds, destroying everything in their path. They return to their home dimension, the Void, when they die in their corporeal form. Religiously, they are defined as Hell's denizens and the servants of Satan.The demons are classified into two "Greater Demons" and "Lesser Demons"
The Greater Demons are demons who are more powerful and have distinctive identities. A significant class of Greater Demons includes the Princes of Hell.Examples where like Lilith, Abbadon
Agramon, Asmodeus,Astaroth,Azazel,Lucifer.....etc
"Lesser demons" the term used to refer to the demons with no identity or intellect and which are so common that they fall under a particular species or classification eg-Asmodei,Kuri,Ravener,Shax....etc
Alexander was able to create a similar set up to the Shadow Hunter world like, The Council is the governing body of the Clave. They are based in Alicante.They write the laws which Shadowhunters and other supernatural beings must observe. The Council also signs the Accords and dictates decisions for official agreements between Shadowhunters and supernatural beings.
The Clave is the collective name for the political body made up of all active Shadowhunters. The Clave interprets the law and makes decisions on important matters that affect the Nephilim, which also sometimes affect other supernatural beings.
All Shadowhunters who recognized the authority of Idris make up the Clave. While Clave members hold a sway in decisions made regarding important matters relevant to their race, final decisions are made by the Council.But these decisions could be overturned by Alexander as he is their leader or king in a way.
Then their is the Iron Sisters who are warriors. Once accepted into the sisterhood, the members are marked with sacred runes, allowing them to shape pure adamas,which is a mystical stone used by Iron Sisters in forging weapons for the Nephilim,particularly seraph blades Only Iron Sisters typically have access to adamas.The adamas is shaped by Iron Sisters into weapons; only the Sisters, who are Marked with sacred runes upon acceptance into the sisterhood, are capable of it.
Thus making them the keepers and the only ones able to craft and handle the metal into tools that Nephilim need. The Sisters call upon the power of the angels to imbue their energy into the blades they make, during which they hear the angels whisper.Their blood is also apparently purified
The Book of the White is a spellbook, one of the most powerful and famous volumes on supernatural work in the world, along with the Gray Book. It is an ancient tome of extreme power known to the beings of the Shadow World and is considered an article of dark magic. It is a small book bound in white leather, with the title written in gilded Latin letters, its contents written in Greek.
The book contains several different recipes for potions, incantations for spells, some of which are black magic, as well as additional information which can be used for research, with the book specializing in binding and unbinding spells, specifically the kind that tie and untie the soul to the body.
Thus the war with the demons began.