Cultivation levels are lowest to highest
G F E D C B A S SS SSS X ranks
The skill books and item and elixirs have the same rank system
G F E D C B A S SS SSS X ranks
So if you want to be a swordsman and you just pass that 10 stats marks you awaken and get an ability according to your class like a swordsman would get a boost to being a swordsman and you rank up from consuming crystal that monsters drop humans also drop half of their Cultivation rank crystal and you cant consume a crystal a rank higher than you.
There are also skill books that are rare drops that are skills for a class or maybe the skill could be used for multi able classes.
In the world, there are dungeons in every town and city you can also find a wild one dungeons and wild monsters to beat dungeons you have to reach the core and beat the final boss and you become the owner of it and you and your organization get boosted drops even tho the boost is small its better than nothing.
After you be the dungeons and bind it the boss would drop a one-time treasure chest that has skills books or items or elixirs.