As of Susanoo release
SS - A completely overpowered character that is both powerful themselves and powerful with teams and all item sets.
S+ - Picks that can fit into basically any comp and still do well. Contains too many benefits to be balance in any current state, meaning they not only require a nerf, but a minor rework.
S - Picks that very seldom perform poorly
A+ - Mostly balanced characters that have an element that allows them to stand out compared to other gods deemed "A"
A - The pinnacle of balance. These gods should not be changed in any way in the current stance of the game
A- - Gods that struggle against S and above picks, but can still be used in a normal match.
B - Generally weak gods that cannot be picked against S and above picks and do well. Can do well in certain situations.
C - Very weak gods that cannot compete with the ranks of A and above
D - Terrible, basically unusable gods that cannot be put into any composition in any context. These gods should be changed immediately.