I was thinking of a loadout card or item that was a rare drop from buyable cases or from very rare drops for doing missions that has cosmetic effects, none that give any player advantages that would make the game pay to play, just certain effects that act as rare items like a knife in counter strike (skins perhaps?) and the card would effect say weapons and augments to give off a glow when you swing a melee weapon or a special explosion effect on the increased explosion damage and such, this idea has a lot of potential in my opinion, people love having a reason to play/grind/buy cases to get these items to show off.
This is just an idea I had when playing and thought that it would be enjoyable to have a flaming katana or something 
I know there is a lot more I could add to this idea but it was just a quick post.
Thank you for reading! 