Skills will go from highest to lowest
SSS(Heavenly, No chance only fate)
SS(Mythical, 0.0001%, Only 1 person in the whole world have it)
S(Legendary, 0.01%, only around 100 or so people have it in the whole world)
A(Epic 0.1%)
B(Rare 2% of getting it during awakened)
C(Uncommon 15% of getting it during awakened)
D(Common 80% of getting it during awakened)
There are 2 type of skills : Active and passive
Skills can grow stronger as the user kills more demon and get attribute point, But low rank skill can never have the real power of a higher skill example are :
D rank user gets its skill lvl to S but a real rank S skill will be tens of times stronger Or even hundreds
But not all low rank skill are useless they are only deemed as useless because no one can have more than 1 skill that's why but a lot of low rank skill can be overpowered if the user has a perfect skill match with it