A documenting system Book system
We can have some kind of books that max 10 pages can be written by players and some kind of bookstore inside the game so, people will make or buy the book item and write things and can sell them in a profit margin on any town city etc. I can hear you saying "whats the point?" There could be many many different types of books that written by players about combos, skills, bugs, guild rules of them and kinda stuff no limit. And i believe it may help new players or cause players inspire eachother or to invest some time in some fun books or interesting. That would be adding some rpg elements to the game. In addition we can have some kind of bookholding trophies that we put on anywhere on openworld so that would also have many different usage that depends on players imagination. Like guiding comers or threating people in some zone or putting some kind of rule set to the entering gate of a city or towns etc etc.