Basic of "Extra"

Power Level - Mortal Rank/ G rank, F ,E,D,C,B,A,S, SS,SSS Rank.

Each Rank also has three minor rank.

Mortal Rank - Normal humans. But not normal anymore. Everyone in this time is born with mana. Even the cripple that is born unable to use any mana has atleast one unit of mana. So even the weakest human is able to do something with mana. Even if not blessed with mana their physique is way batter then normal human.

Ability - Everyone is born with atleast one ability. Can be ranked from F to SSS Rank. Someone might born with the most useless ability. But they will still get something. Common knowledge is that ability is decided from birth. Ability can not be changed nor replaced.

Skill- Sometimes people get it after clearing dungeon, killing monsters. And job changing will definitely bring new skills.

Job- After the breakthrough from mortal rank and reaching F- Rank, Status Window is available for everyone. People can get job after that. Jobs can be upgraded to better version and more skills can be achieved. But the conditions are different from person to person.

Techniques / Arts - These are hand made skills made by humans. No matter who is using it, a real "Skill" is same with everyone, same mana cost, same effect. But depending on user the effect of "Techniques" are different. Depending on affinity level and the mana input the affect is different from person to person. The result of an skill cannot be changed. But people have better control over Techniques, can manipulate it's effect. Techniques has way lower mana cost then Skills. The body has a certain limit of skills it can hold. Techniques is all about memorising certain way of using mana. There is no limit of how many someone can learn.

Spell - It's the same as arts. But it's used by mage. Techniques mostly works with breathing and controlling the mana inside one's body. Spell is about casting and controlling mana outside the body.

Affinity - An element a person in comparable with. Can be leveled by Low, Intermediate/ Mid, High, Peak. Each element affinity is also ranked as common,uncommon,rare and unique . People with no affinity exist. But it's more like a blessing. Its more wanted then a uncommon mid leveled affinity. Someone with an affinity can not use element that oppose their affinity or in no way related to their affinity. People with no affinity can use any elements they want but not as powerful as someone with affinity for that. Like a Jake of all trades but master of none.

At the beginning people with no affinity was seen as the weakest. But 300 years ago the hero who mastered 10 different elements slayed the Demon King despite having no affinity. Since then the value of a no affinity person skyrocketed.