@Riot: Different Mana interactions.

I was just wondering if at any point you'd tried different ways to use mana as a resource beyond (damage/health/shield) scaling. For example, have you considered creating an ability where the champion needed x amount of mana to use an ability, but it didn't consume x mana. Going OOM could still prevent you from using the ability, but it would otherwise have no restrictions above a certain threshold. A low mana pool would still be a sign of weakness and this ability could remain costless.