Spell vamp and rylais should apply fully to AoE abilities if they hit one target

How does that work with line skillshots?

Ahri's Orb of Deception being the most extreme case. You cannot know how many targets it hits until it completes, something that can take longer than Rylai's slow duration.

no, too much useless processing.

Ziggs throws a bomb at 6 minions at level 9, restoring 20% of the ~2,500 collective HP for that wave if he can 1-shot them. Spending 90 mana to restore 500 HP.

Maybe you should just use AoE abilities to hit at least 3 targets?

Karthus becomes God.

Yes please. I want this for Cass q. (While assuming her poison ever does decent damage again.)

Spell vamp shouldn't be an item stat, once you change it to something that each champ who needs it has individually, then you can balance it appropriately.

Rylai's should have less of a reduced effect for AOE, yes, but not full 100% effectiveness, it would make AOE too strong imo. At this point though, it could handle being made 1/3 less effective, rather than 2/3 less effective like it is now for AOE.