Soraka Change
I assume this will never happen, but personally I thought it was an interesting idea. Instead of Soraka's heal costing HP, what if she took magic (Physical or Mixed) instead? making it so resistances are now applied.
If this were to happen Soraka wouldn't need to always build HP. Allowing her to also build tanky MR (or Armor) items giving players more options.
(And before people say 'that's op' numbers can be tweaked )
Edit Please Note: I am not talking about building health on Soraka. I am talking about her instead of losing X HP she takes X damage, which would allow for resistances to apply.