What if Retired Skins Came Back as Hextech Gem Skins?
Obviously there would be special borders and such identifying the originals (in fact Grey Warwick seems to already have a border loading in?).
What if retired skins were available as very rare hextech drops from chests that require gemstones to turn into permanents? It'd still make them rare and hard to get but give people a small chance at obtaining them. I think I've only seen Darius' gem skin once, Hextech Annie once, and I have yet to see Vayne's. They are still incredibly rare.
I for one think Grey Warwick is a gorgeous skin and would love to be able to use it, but I also think that if it is ever brought back there should be identifying marks and borders show who got it through recruit a friend originally and who got it through hextech.