Ranks

F rank

E rank

D rak

C rank

B rank

A rank

S rank

X rank

After X rank all ranks are now named realms

Ceta Realm

Primordium Realm

Dungeon Ranks

Bronze

Silver

Gold

Platinum

Diamond

Bronze dungeons allow entry for F to D ranks

Silver for C and B rank

Gold for A rank

Platinum for S rank

Diamond for X rank

and so on

Main Classes : Warrior , Mage, Tank , Assasin

Combine them as you see fit and then combine those combinations then share them .

Although be warned I may or may not put your created classes into the story.