Give all spellvamp and lifesteal the Morgana passive treatment.
Morganas new passive only heals her when she damages champions, large minions, or large monsters.
Do this for all champions with spellcamp and lifesteal. There is a massive number of champions that use their absolutly absurd amount of healing in their kits to stay healthy simply from last hitting minions, they just heal off the minions and don't engage the enemy laner at all unless they have a overwhelming HP advantage from their selfhealing.
Just look at champions llike
, they all basically have the same pettern of use our crazy self healing to stay at full HP just by using their healing skills on minions. Give them the Morgana treatment to remove their ability to passively sustain in lane and force them to actually fight they opponents.
Heck do it for all lifesteal from items. No need for an ADC at 50 HP to walk into a jungle find one camp and go up to full HP in two auto attacks.