Visual representation of high leveled units
I know it has been said before but I think that high leveled units should look different from low level units. I don't mean changing units on every "level up" but maybe like every 3 levels or so. That doesn't mean that additional visual armor/weapons has to be added on every visual change. The change could include for example added tattoos on unit's armor/weapons/skins and so on.
I think some type of system similar to this could really add to the atmosphere of the game.