So here is the idea, bungie would need to be on board for this of course. The idea is this, u have a certain weapon, be it primary or secondary that u have used more then others. You love this weapon and want it to evolve with you. Here is the catch, it must be an exotic. Reason for this is it narrows down the work for destiny a bit and exotic weapons are carried forward from season to season. This weapon of yours would get a unique perk only you and maybe 20 others could get. Be it extra ammo, faster rate of fire, explosive rounds. The perk would be unique to how "you" use the weapon. So all of the data the destiny already collects could be used to help determine what that perk for you and your chosen weapon would be. Yes I know, I could become unfair in pvp. That's why the upgrade wouldn't be allowed to be used in pvp, only pve.