I suggest level caps on armors and weapons, such as: Jagged Saber requires level 50 attack to wield or Titanium Plate requires level 60 defense to wear or along the lines of that. Remove Human nexus and replace with that
Not sure if it would change anything but yeah..just makes people have to actually train a bit to be able to wear certain stuff.
Oh and a/d caps? Cap at like 100 or 150 or something? Idk, just more stuff for you to consider.