Guide to God Slayer!
Here's a one stop shop for the finer details of God Slayer in case you have any questions. This is all revealed within the story, spoiler warning, but in case you forget anything it will be here as well. To avoid giving away important parts of the series, I'll come back and update this as new things come up.
//Divine Beings//
Holy:
*The King of the Heavens: The highest position in the Heavens and the God who rules all other Gods.
*Gods: Serve under the King of the Heavens. Each God has a specific aspect of life that they oversee(i.e God of War, God of Time).
*Seraphs: Direct subordinates of the Gods. They are the highest rank of angel and are usually the next in line for God ascension when the position becomes available. Each God will usually only have 1-2.
*Archangels: Reports to the Seraphs in most cases. They are usually the ones sent to lead attacks As Seraphs and Gods don't report to the front line unless absolutely necessary.
*Angels: The rank and file of the Heavens. Are sent in groups/masses to destroy targets.
*Holy Slayer: A mortal soul that is blessed with holy energy and granted divine power to destroy enemies of the Heavens. Their divine power is regulated by a system. A very rare occurrence.
Unholy:
*Queen of the Underworld: The highest position in the Underworld and oversees all demons, devils, and slayers.
*Devils: Highest rank of demon: their power can rival Seraphs and on occasion Gods. In the Underworld, everyone reports to the Queen so they have no direct reports. Their actions are behind much of the tragedies in life.
*Demons: The lowest rank in the Underworld. They also report to the Queen.
*Unholy Slayer: A mortal soul that is blessed with unholy energy and granted divine power to destroy enemies of the Underworld. Their divine power is regulated by the God Core System. Their system allows them to achieve power as high as that of a God based on consumed cores.
*Contracted Slayer: A slayer that has decided to be employed by the government for their services. They receive certain privileges and perks in exchange for abiding by bylaws that regulate how they can operate.
*Freelance Slayer: A slayer that has decided to work completely on their own and thereby not abide by the slayer bylaws. These slayers are usually more quirky as they spend their days slaying and consuming cores to become as powerful as possible. They are offered no protections by the government however.
*Rogue Divine Beings: These are beings that are not of holy or unholy alignment, but they still possess divine energy. They are only able to use Rogue Divine Arts since they can't use holy/unholy weapons.
//System//
*God Core System: A hijacked connection to the One Core that allows slayers to consume other cores in order to strengthen their connection to the system and thereby allowing them to access more of its power. Mortal souls should otherwise not be able to utilize the One Core's power. The God Core System can be enhanced and leveled up based on cores consumed and experience from battle. In theory, if a slayer were to consume enough cores they could match up to a God.
*System Abilities: As the God Core System is enhanced, abilities can be granted based on the user and the weapon they wield. Abilities can also be gifted through the Queen of the Underworld at her discretion.
*System Administrator: A digital program, "Admin", was installed into the God Core System in order to maintain it for all connected slayers. Her voice is the one that slayers hear when they receive system updates or when they consume cores. Her appearance can be that of a teenage girl.
*Cores: The very essence of a holy/unholy being's power. Every core connects back to the same source of power, the One Core, that allows them to wield their weapons, perform Arts, as well as enhance their own body. All high ranking demons/angels, Gods, and slayers have an innate core that serves as their connection to the system. Lesser angels and demons have cores that hold holy/unholy energy but are not directly connected to the core system. So they can't strengthen their connection unless they are promoted by a God and given access. A core only shows itself when said divine being has been killed.
*The One Core: The core that all high ranking holy/unholy beings connect back with their own core in order to utilize divine energy. It is an ancient power that no one truly understands, but has been around since the creation of time. Low ranking holy/unholy beings are allotted divine power but do not have a connection to the core.
*Arts: Spells/attacks that are done by manifesting divine energy. There are multiple types of Arts as it is something that is used by all types of divine beings. Such as Rogue Arts, Holy Arts, Unholy Arts, God Arts, etc. A deep understanding of the specific Art must be achieved in order for it to be utilized. These range from conjuring elements, healing, shields, widespread destruction, etc.
*Arts 'Kai' Version: Upgraded forms of spells/attacks that are done by manifesting divine energy. The Kai version can be up to double the power of the original, but takes even more ingeunity to pull off. If not experienced with it, it can completely drain your power or backfire on the user.
*Holy: Energy source used in the Heavens. Needed to use blessed weapons.
*Unholy: Energy source used in the Underworld. Needed to use cursed weapons.
*Divine Energy: The basis for all energy of divine beings. It fuels their cores, their Arts, their abilities, and their weapons. The stronger the divine energy of an individual the more widespread it is felt. It can generate a 'pressure' that can be felt by those around them. Higher ranking angels/demons are able to sense the divine energy of another.
*Pure Connection: The strongest type of connection to the One Core. This is the type of connection that all holy/unholy divine beings have with the exception of slayers. Since slayers are more considered to be demi-gods, their connection is still hampered by human attachments/qualities. This creates a less stable and potent connection to the One Core.
*Divine Connection: The connection created when two divine beings have matching energies. This allows them to see into the other's energy which connects to every part of their being. A Divine Connection can be used for many purposes, but the rarity of it happening doesn't provide enough concrete evidence if it actually works.
//Weapons//
Cursed weapons: Weapons used by users of unholy energy. They are usually embedded with dark feelings, cursed spirits, violent intentions, etc. They are the only weapon that can kill a divine being of the Heavens.
Blessed weapons: Weapons used by users of holy energy. They are usually embedded with feelings of goodness, sacred incantations, etc. They are the only weapon that can kill a divine being of the Underworld.
Weapon Rating System: Weapons are rated from 1-3 stars for most divine beings; however there are 4-5 star weapons that can only be wielded by God tier beings. Trying to wield a weapon outside of your capability could lead to an overdrain on their divine energy and result in death.
**Non-divine weapons can be laced with holy/unholy energy to achieve a low grade of these effects. It's enough to cause above average damage, but not enough to completely wipe out the soul of the victim**
//Slayer Stats// (Note: These aren't fully implemented until Chapter 63!)
*System Connection: How strong and stable their connection to the One Core is. The higher the percentage the more power they can draw from it. Some abilities can only be unlocked at specific system connection percentages.
*Mental Stability: How strong/weak their current mental state is. The lower the percentage, the more unstable their attacks become or the slayer may become more erratic. Divine power was not meant for mortal souls so their mental state can influence their power.
*Experience: Gained from each battle and helps level up their system. Not as substantial as consuming a core, but has its benefits. The bigger the enemy the more experience that is gained. [[Authors Note: Experience isn't tracked until later in the series - up until then it is still gathered and slayers do grow slightly stronger, but there's no way of knowing how much has been gained until chapter 63.]]
*Divine Energy: The amount of divine energy that a slayer has currently out of their max divine energy. Using weapons and Arts drain energy; if they use up all of their energy they will be in a very vunerable state. If they try to use energy past this point they could kill themselves. This number is raised as the system is leveled up.
*Slayer Rank: A letter rating based on the cumulative of all their stats. This ranges from C to S just like they do with the divine forces that invade Earth.
Gifts
-- Gift
received Weekly Power Status
-- Power
Ranking 
-- Power
stone