Create + damage limited edition items that can be sold by Kano for a little extra . For example a item that is lets say 540 attack / 330 def sells for 50 un but comes with + 5 damage in fights and may be stacked (maybe 5 time limit so after buying 5 the damage will not stack further ) .Or another example a item with 330 attack /540 def can come with +2 % defense in fights .Add a little extra sparkle to the game and bring in some revenue for Kano