E = Those with 50-250 Mana

D = Those with 250-400 Mana

C = Those with 400-1800 Mana

B = Those with 1800-6500 Mana

A = Those with 6500-52000 Mana

S = Those with 52000-235000 Mana

These are the basic rankings given to mages pursuing a career as a soldier.

Emperor = 480000< Mana

This is the rank that less than 500 have obtained

Supernova = Top 10 strongest mages, whos mana levels are all, 8450000<

Similarly magical attacks follow the same ranking of Power, D > E, etc. For reference, if an E class was to put all his Mana into an attack, it could destroy a building!