F = The base value and it is estimated to be 10 times more powerful than an average human.
F+ = The base value and it is estimated to be 30 times more powerful than an average human/Low-Class Devils.
E = The base value and it is estimated to be 50 times more powerful than an average human/ Mid-Class devils.
D = high class devils = 4-6 winged angels
C = Ultimate Class / 8-10 winged angels/ Low-Class Dragon
B = Maou Class / 12 winged angels / Lower-Class gods / Mid-Class Dragon
A = Super Devil / higher Gods / Evil Dragons
Ex = The 'Ex' rank is applied when the power cannot be classified in the normal system and is in a league of its own. While it can be applied to extremely powerful creatures such as the Great Red, Ophis and Trihexia.
Sword Stages:
Sword apprentice: First time Using Sword.
Sword user: Can atleast do Sword
sparring.
Sword Expert : Can Cut rock cleanly
Sword Master : Can cut Steel.
Sword Heart : Can Cut a person or Not,this stage can only be attained if you can reinforce you Will on the weapon.
Sword king : Can Cut a whole House clean.
Sword Emperor : Can cut moutains in half.
Sword God: Can cut Gods.